\psset{unit=0.45cm}
%
\pspicture(-11.5,-5)(17,8.5)
% The frames indicating the ending levels:
\psframe[linewidth=0.01,linecolor=black,fillstyle=solid,fillcolor=gray](-11,6.1)(16.5,6.9)
\psframe[linewidth=0.01,linecolor=black,fillstyle=solid,fillcolor=gray](-11,1.1)(16.5,1.9)
\psframe[linewidth=0.01,linecolor=black,fillstyle=solid,fillcolor=gray](-11,-3.9)(16.5,-3.1)
\rput(-9,6.5){\psframebox[fillstyle=solid,fillcolor=white,framearc=0.3]{{\tiny\bf level N}}}
\rput(-9,1.5){\psframebox[fillstyle=solid,fillcolor=white,framearc=0.3]{{\tiny\bf level N}}}
\rput(-9,-3.5){\psframebox[fillstyle=solid,fillcolor=white,framearc=0.3]{{\tiny\bf level N}}}
% The frames indicating the recoloured points:
\psframe[linewidth=0.125,linecolor=black,framearc=0.3](15.33,4.33)(16.66,8.66)
\psframe[linewidth=0.125,linecolor=black,framearc=0.3](6.33,-0.67)(7.66,3.66)
\psframe[linewidth=0.125,linecolor=black,framearc=0.3](-2.66,-5.67)(-1.33,-1.34)
% The frames indicating double-points:
\psframe[linewidth=0.01,linecolor=black,fillstyle=solid,fillcolor=lightgray,framearc=0.3](-6.5,5.5)(-2.5,7.5)
\psframe[linewidth=0.01,linecolor=black,fillstyle=solid,fillcolor=lightgray,framearc=0.3](-0.5,5.5)(2.5,7.5)
\psframe[linewidth=0.01,linecolor=black,fillstyle=solid,fillcolor=lightgray,framearc=0.3](4.5,5.5)(6.5,7.5)
\psframe[linewidth=0.01,linecolor=black,fillstyle=solid,fillcolor=lightgray,framearc=0.3](8.5,5.5)(14.5,7.5)
\psframe[linewidth=0.01,linecolor=black,fillstyle=solid,fillcolor=lightgray,framearc=0.3](-6.5,0.5)(-2.5,2.5)
\psframe[linewidth=0.01,linecolor=black,fillstyle=solid,fillcolor=lightgray,framearc=0.3](-0.5,0.5)(2.5,2.5)
\psframe[linewidth=0.01,linecolor=black,fillstyle=solid,fillcolor=lightgray,framearc=0.3](4.5,0.5)(6.5,2.5)
\psframe[linewidth=0.01,linecolor=black,fillstyle=solid,fillcolor=lightgray,framearc=0.3](8.5,0.5)(14.5,2.5)
\psframe[linewidth=0.01,linecolor=black,fillstyle=solid,fillcolor=lightgray,framearc=0.3](-6.5,-4.5)(-2.5,-2.5)
\psframe[linewidth=0.01,linecolor=black,fillstyle=solid,fillcolor=lightgray,framearc=0.3](-0.5,-4.5)(2.5,-2.5)
\psframe[linewidth=0.01,linecolor=black,fillstyle=solid,fillcolor=lightgray,framearc=0.3](4.5,-4.5)(6.5,-2.5)
\psframe[linewidth=0.01,linecolor=black,fillstyle=solid,fillcolor=lightgray,framearc=0.3](8.5,-4.5)(14.5,-2.5)
% The grid for the ending points:
% Vertical grid lines:
\psline[linewidth=0.085,linecolor=gray](-6,5)(-6,8)
\psline[linewidth=0.085,linecolor=gray](-5,5)(-5,8)
\psline[linewidth=0.085,linecolor=gray](-4,5)(-4,8)
\psline[linewidth=0.085,linecolor=gray](-3,5)(-3,8)
\psline[linewidth=0.085,linecolor=gray](-2,5)(-2,8)
\psline[linewidth=0.085,linecolor=gray](-1,5)(-1,8)
\psline[linewidth=0.085,linecolor=gray](0,5)(0,8)
\psline[linewidth=0.085,linecolor=gray](1,5)(1,8)
\psline[linewidth=0.085,linecolor=gray](2,5)(2,8)
\psline[linewidth=0.085,linecolor=gray](3,5)(3,8)
\psline[linewidth=0.085,linecolor=gray](4,5)(4,8)
\psline[linewidth=0.085,linecolor=gray](5,5)(5,8)
\psline[linewidth=0.085,linecolor=gray](6,5)(6,8)
\psline[linewidth=0.085,linecolor=gray](7,5)(7,8)
\psline[linewidth=0.085,linecolor=gray](8,5)(8,8)
\psline[linewidth=0.085,linecolor=gray](9,5)(9,8)
\psline[linewidth=0.085,linecolor=gray](10,5)(10,8)
\psline[linewidth=0.085,linecolor=gray](11,5)(11,8)
\psline[linewidth=0.085,linecolor=gray](12,5)(12,8)
\psline[linewidth=0.085,linecolor=gray](13,5)(13,8)
\psline[linewidth=0.085,linecolor=gray](14,5)(14,8)
\psline[linewidth=0.085,linecolor=gray](15,5)(15,8)
\psline[linewidth=0.085,linecolor=gray](16,5)(16,8)
% Vertical grid lines:
\psline[linewidth=0.085,linecolor=gray](-6,0.)(-6,3.)
\psline[linewidth=0.085,linecolor=gray](-5,0.)(-5,3.)
\psline[linewidth=0.085,linecolor=gray](-4,0.)(-4,3.)
\psline[linewidth=0.085,linecolor=gray](-3,0.)(-3,3.)
\psline[linewidth=0.085,linecolor=gray](-2,0.)(-2,3.)
\psline[linewidth=0.085,linecolor=gray](-1,0.)(-1,3.)
\psline[linewidth=0.085,linecolor=gray](0,0.)(0,3.)
\psline[linewidth=0.085,linecolor=gray](1,0.)(1,3.)
\psline[linewidth=0.085,linecolor=gray](2,0.)(2,3.)
\psline[linewidth=0.085,linecolor=gray](3,0.)(3,3.)
\psline[linewidth=0.085,linecolor=gray](4,0.)(4,3.)
\psline[linewidth=0.085,linecolor=gray](5,0.)(5,3.)
\psline[linewidth=0.085,linecolor=gray](6,0.)(6,3.)
\psline[linewidth=0.085,linecolor=gray](7,0.)(7,3.)
\psline[linewidth=0.085,linecolor=gray](8,0.)(8,3.)
\psline[linewidth=0.085,linecolor=gray](9,0.)(9,3.)
\psline[linewidth=0.085,linecolor=gray](10,0.)(10,3.)
\psline[linewidth=0.085,linecolor=gray](11,0.)(11,3.)
\psline[linewidth=0.085,linecolor=gray](12,0.)(12,3.)
\psline[linewidth=0.085,linecolor=gray](13,0.)(13,3.)
\psline[linewidth=0.085,linecolor=gray](14,0.)(14,3.)
\psline[linewidth=0.085,linecolor=gray](15,0.)(15,3.)
\psline[linewidth=0.085,linecolor=gray](16,0.)(16,3.)
% Vertical grid lines:
\psline[linewidth=0.085,linecolor=gray](-6,-5.)(-6,-2.)
\psline[linewidth=0.085,linecolor=gray](-5,-5.)(-5,-2.)
\psline[linewidth=0.085,linecolor=gray](-4,-5.)(-4,-2.)
\psline[linewidth=0.085,linecolor=gray](-3,-5.)(-3,-2.)
\psline[linewidth=0.085,linecolor=gray](-2,-5.)(-2,-2.)
\psline[linewidth=0.085,linecolor=gray](-1,-5.)(-1,-2.)
\psline[linewidth=0.085,linecolor=gray](0,-5.)(0,-2.)
\psline[linewidth=0.085,linecolor=gray](1,-5.)(1,-2.)
\psline[linewidth=0.085,linecolor=gray](2,-5.)(2,-2.)
\psline[linewidth=0.085,linecolor=gray](3,-5.)(3,-2.)
\psline[linewidth=0.085,linecolor=gray](4,-5.)(4,-2.)
\psline[linewidth=0.085,linecolor=gray](5,-5.)(5,-2.)
\psline[linewidth=0.085,linecolor=gray](6,-5.)(6,-2.)
\psline[linewidth=0.085,linecolor=gray](7,-5.)(7,-2.)
\psline[linewidth=0.085,linecolor=gray](8,-5.)(8,-2.)
\psline[linewidth=0.085,linecolor=gray](9,-5.)(9,-2.)
\psline[linewidth=0.085,linecolor=gray](10,-5.)(10,-2.)
\psline[linewidth=0.085,linecolor=gray](11,-5.)(11,-2.)
\psline[linewidth=0.085,linecolor=gray](12,-5.)(12,-2.)
\psline[linewidth=0.085,linecolor=gray](13,-5.)(13,-2.)
\psline[linewidth=0.085,linecolor=gray](14,-5.)(14,-2.)
\psline[linewidth=0.085,linecolor=gray](15,-5.)(15,-2.)
\psline[linewidth=0.085,linecolor=gray](16,-5.)(16,-2.)
% Ray of labels:
\rput(-6,4.7){${\scriptscriptstyle -7}$}
\rput(-5,4.7){${\scriptscriptstyle -6}$}
\rput(-4,4.7){${\scriptscriptstyle -5}$}
\rput(-3,4.7){${\scriptscriptstyle -4}$}
\rput(-2,4.7){${\scriptscriptstyle -3}$}
\rput(-1,4.7){${\scriptscriptstyle -2}$}
\rput(0,4.7){${\scriptscriptstyle -1}$}
\rput(1,4.7){${\scriptscriptstyle 0}$}
\rput(2,4.7){${\scriptscriptstyle 1}$}
\rput(3,4.7){${\scriptscriptstyle 2}$}
\rput(4,4.7){${\scriptscriptstyle 3}$}
\rput(5,4.7){${\scriptscriptstyle 4}$}
\rput(6,4.7){${\scriptscriptstyle 5}$}
\rput(7,4.7){${\scriptscriptstyle 6}$}
\rput(8,4.7){${\scriptscriptstyle 7}$}
\rput(9,4.7){${\scriptscriptstyle 8}$}
\rput(10,4.7){${\scriptscriptstyle 9}$}
\rput(11,4.7){${\scriptscriptstyle 10}$}
\rput(12,4.7){${\scriptscriptstyle 11}$}
\rput(13,4.7){${\scriptscriptstyle 12}$}
\rput(14,4.7){${\scriptscriptstyle 13}$}
\rput(15,4.7){${\scriptscriptstyle 14}$}
\rput(16,4.7){${\scriptscriptstyle 15}$}
% Ray of labels:
\rput(-6,-0.3){${\scriptscriptstyle -7}$}
\rput(-5,-0.3){${\scriptscriptstyle -6}$}
\rput(-4,-0.3){${\scriptscriptstyle -5}$}
\rput(-3,-0.3){${\scriptscriptstyle -4}$}
\rput(-2,-0.3){${\scriptscriptstyle -3}$}
\rput(-1,-0.3){${\scriptscriptstyle -2}$}
\rput(0,-0.3){${\scriptscriptstyle -1}$}
\rput(1,-0.3){${\scriptscriptstyle 0}$}
\rput(2,-0.3){${\scriptscriptstyle 1}$}
\rput(3,-0.3){${\scriptscriptstyle 2}$}
\rput(4,-0.3){${\scriptscriptstyle 3}$}
\rput(5,-0.3){${\scriptscriptstyle 4}$}
\rput(6,-0.3){${\scriptscriptstyle 5}$}
\rput(7,-0.3){${\scriptscriptstyle 6}$}
\rput(8,-0.3){${\scriptscriptstyle 7}$}
\rput(9,-0.3){${\scriptscriptstyle 8}$}
\rput(10,-0.3){${\scriptscriptstyle 9}$}
\rput(11,-0.3){${\scriptscriptstyle 10}$}
\rput(12,-0.3){${\scriptscriptstyle 11}$}
\rput(13,-0.3){${\scriptscriptstyle 12}$}
\rput(14,-0.3){${\scriptscriptstyle 13}$}
\rput(15,-0.3){${\scriptscriptstyle 14}$}
\rput(16,-0.3){${\scriptscriptstyle 15}$}
% Ray of labels:
\rput(-6,-5.3){${\scriptscriptstyle -7}$}
\rput(-5,-5.3){${\scriptscriptstyle -6}$}
\rput(-4,-5.3){${\scriptscriptstyle -5}$}
\rput(-3,-5.3){${\scriptscriptstyle -4}$}
\rput(-2,-5.3){${\scriptscriptstyle -3}$}
\rput(-1,-5.3){${\scriptscriptstyle -2}$}
\rput(0,-5.3){${\scriptscriptstyle -1}$}
\rput(1,-5.3){${\scriptscriptstyle 0}$}
\rput(2,-5.3){${\scriptscriptstyle 1}$}
\rput(3,-5.3){${\scriptscriptstyle 2}$}
\rput(4,-5.3){${\scriptscriptstyle 3}$}
\rput(5,-5.3){${\scriptscriptstyle 4}$}
\rput(6,-5.3){${\scriptscriptstyle 5}$}
\rput(7,-5.3){${\scriptscriptstyle 6}$}
\rput(8,-5.3){${\scriptscriptstyle 7}$}
\rput(9,-5.3){${\scriptscriptstyle 8}$}
\rput(10,-5.3){${\scriptscriptstyle 9}$}
\rput(11,-5.3){${\scriptscriptstyle 10}$}
\rput(12,-5.3){${\scriptscriptstyle 11}$}
\rput(13,-5.3){${\scriptscriptstyle 12}$}
\rput(14,-5.3){${\scriptscriptstyle 13}$}
\rput(15,-5.3){${\scriptscriptstyle 14}$}
\rput(16,-5.3){${\scriptscriptstyle 15}$}
% Black/white ending points, no recolouring:
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](16,7){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](14,7){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](13,7){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](10,7){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](9,7){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](6,7){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](5,7){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](3,7){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](2,7){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](0,7){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](-3,7){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](-6,7){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](14,6){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](13,6){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](10,6){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](9,6){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](7,6){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](6,6){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](5,6){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](2,6){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](0,6){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](-2,6){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](-3,6){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](-6,6){0.3}
% The triangles indicating the single ending points
% The up-triangles:
\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](6.67,5.15)(7.33,5.15)(7,5.6)
\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](-2.33,5.15)(-1.67,5.15)(-2,5.6)
% The down-triangles:
\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](15.67,7.85)(16.33,7.85)(16,7.4)
\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](2.67,7.85)(3.33,7.85)(3,7.4)
% Black/white ending points, first recolouring:
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](14,2.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](13,2.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](10,2.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](9,2.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](7,2.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](6,2.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](5,2.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](3,2.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](2,2.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](0,2.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](-3,2.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](-6,2.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](16,1.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](14,1.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](13,1.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](10,1.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](9,1.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](6,1.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](5,1.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](2,1.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](0,1.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](-2,1.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](-3,1.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](-6,1.){0.3}
% The triangles indicating the single ending points
% The up-triangles:
\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](15.67,0.15)(16.33,0.15)(16,0.6)
\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](-2.33,0.15)(-1.67,0.15)(-2,0.6)
% The down-triangles:
\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](6.67,2.85)(7.33,2.85)(7,2.4)
\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](2.67,2.85)(3.33,2.85)(3,2.4)
% Black/white ending points, first recolouring:
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](14,-3.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](13,-3.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](10,-3.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](9,-3.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](6,-3.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](5,-3.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](3,-3.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](2,-3.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](0,-3.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](-2,-3.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](-3,-3.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](-6,-3.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](16,-4.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](14,-4.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](13,-4.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](10,-4.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](9,-4.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](7,-4.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](6,-4.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](5,-4.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](2,-4.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](0,-4.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](-3,-4.){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](-6,-4.){0.3}
% The triangles indicating the single ending points
% The up-triangles:
\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](15.67,-4.85)(16.33,-4.85)(16,-4.4)
\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](6.67,-4.85)(7.33,-4.85)(7,-4.4)
% The down-triangles:
\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](-2.33,-2.15)(-1.67,-2.15)(-2,-2.6)
\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](2.67,-2.15)(3.33,-2.15)(3,-2.6)
%
\endpspicture