\psset{unit=0.45cm}
%
\pspicture(-12,-12)(17,9)
% The frames indicating starting/ending levels:
\psframe[linewidth=0.01,linecolor=black,fillstyle=solid,fillcolor=gray](-11.5,6.1)(16.5,6.9)
\psframe[linewidth=0.01,linecolor=black,fillstyle=solid,fillcolor=gray](-11.5,0.1)(16.5,0.9)
% Labels for the starting/ending levels:
\rput(-9,6.5){\psframebox[fillstyle=solid,fillcolor=white,framearc=0.3]{{\tiny\bf level N}}}
\rput(14,0.5){\psframebox[fillstyle=solid,fillcolor=white,framearc=0.3]{{\tiny\bf level 1}}}
% 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](-7.66,-1.66)(-6.33,2.66)
\psframe[linewidth=0.125,linecolor=black,framearc=0.3](5.33,-1.66)(6.66,2.66)
\psframe[linewidth=0.125,linecolor=black,framearc=0.3](10.33,-1.66)(11.66,2.66)
% The arrows indicating the recolouring:
\psline[linecolor=black,linewidth=0.25]{<->}(16,4)(11,3)
\psline[linecolor=black,linewidth=0.25]{<->}(6,3)(-7,3)
% 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](-4.5,-0.5)(5.5,1.5)
\psframe[linewidth=0.01,linecolor=black,fillstyle=solid,fillcolor=lightgray,framearc=0.3](8.5,-0.5)(10.5,1.5)
% 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)
% 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){${\scriptscriptstyle 15}$}
% Vertical grid lines:
\psline[linewidth=0.085,linecolor=gray](-11,-1)(-11,2)
\psline[linewidth=0.085,linecolor=gray](-10,-1)(-10,2)
\psline[linewidth=0.085,linecolor=gray](-9,-1)(-9,2)
\psline[linewidth=0.085,linecolor=gray](-8,-1)(-8,2)
\psline[linewidth=0.085,linecolor=gray](-7,-1)(-7,2)
\psline[linewidth=0.085,linecolor=gray](-6,-1)(-6,2)
\psline[linewidth=0.085,linecolor=gray](-5,-1)(-5,2)
\psline[linewidth=0.085,linecolor=gray](-4,-1)(-4,2)
\psline[linewidth=0.085,linecolor=gray](-3,-1)(-3,2)
\psline[linewidth=0.085,linecolor=gray](-2,-1)(-2,2)
\psline[linewidth=0.085,linecolor=gray](-1,-1)(-1,2)
\psline[linewidth=0.085,linecolor=gray](0,-1)(0,2)
\psline[linewidth=0.085,linecolor=gray](1,-1)(1,2)
\psline[linewidth=0.085,linecolor=gray](2,-1)(2,2)
\psline[linewidth=0.085,linecolor=gray](3,-1)(3,2)
\psline[linewidth=0.085,linecolor=gray](4,-1)(4,2)
\psline[linewidth=0.085,linecolor=gray](5,-1)(5,2)
\psline[linewidth=0.085,linecolor=gray](6,-1)(6,2)
\psline[linewidth=0.085,linecolor=gray](7,-1)(7,2)
\psline[linewidth=0.085,linecolor=gray](8,-1)(8,2)
\psline[linewidth=0.085,linecolor=gray](9,-1)(9,2)
\psline[linewidth=0.085,linecolor=gray](10,-1)(10,2)
\psline[linewidth=0.085,linecolor=gray](11,-1)(11,2)
% Ray of labels:
\rput(-11,2.3){${\scriptscriptstyle -12}$}
\rput(-10,2.3){${\scriptscriptstyle -11}$}
\rput(-9,2.3){${\scriptscriptstyle -10}$}
\rput(-8,2.3){${\scriptscriptstyle -9}$}
\rput(-7,2.3){${\scriptscriptstyle -8}$}
\rput(-6,2.3){${\scriptscriptstyle -7}$}
\rput(-5,2.3){${\scriptscriptstyle -6}$}
\rput(-4,2.3){${\scriptscriptstyle -5}$}
\rput(-3,2.3){${\scriptscriptstyle -4}$}
\rput(-2,2.3){${\scriptscriptstyle -3}$}
\rput(-1,2.3){${\scriptscriptstyle -2}$}
\rput(0,2.3){${\scriptscriptstyle -1}$}
\rput(1,2.3){${\scriptscriptstyle 0}$}
\rput(2,2.3){${\scriptscriptstyle 1}$}
\rput(3,2.3){${\scriptscriptstyle 2}$}
\rput(4,2.3){${\scriptscriptstyle 3}$}
\rput(5,2.3){${\scriptscriptstyle 4}$}
\rput(6,2.3){${\scriptscriptstyle 5}$}
\rput(7,2.3){${\scriptscriptstyle 6}$}
\rput(8,2.3){${\scriptscriptstyle 7}$}
\rput(9,2.3){${\scriptscriptstyle 8}$}
\rput(10,2.3){${\scriptscriptstyle 9}$}
\rput(11,2.3){${\scriptscriptstyle 10}$}
% Black/white starting/ending points
\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=white](10,0){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](9,0){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](6,0){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](5,0){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](4,0){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](2,0){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](0,0){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](-1,0){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](-2,0){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](-4,0){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](-9,0){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](16,6){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}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](11,1){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](5,1){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](4,1){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](-1,1){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](-4,1){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](-7,1){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](-8,1){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](-11,1){0.3}
% The triangles indicating the single starting/ending points
% The up-triangles:
\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](15.67,5.15)(16.33,5.15)(16,5.6)
\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)
\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](-11.33,0.15)(-10.67,0.15)(-11,0.6)
\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](-8.33,0.15)(-7.67,0.15)(-8,0.6)
\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](10.67,0.15)(11.33,0.15)(11,0.6)
\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](-7.33,0.15)(-6.67,0.15)(-7,0.6)
% The down-triangles:
\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](2.67,7.85)(3.33,7.85)(3,7.4)
\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](-9.33,0.85)(-8.67,0.85)(-9,0.4)
\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](5.67,0.85)(6.33,0.85)(6,0.4)
\pscircle[linewidth=0.2,linecolor=gray](2.5,-6.5){3.5}
\psline[linewidth=0.085,linecolor=gray](-2.75,-6.5)(7.75,-6.5)
\psline[linewidth=0.085,linecolor=gray](5.33156,-4.44275)(6.30238,-3.73741)
\psline[linewidth=0.085,linecolor=gray](3.58156,-3.1713)(3.95238,-2.03003)
\psline[linewidth=0.085,linecolor=gray](1.41844,-3.1713)(1.04762,-2.03003)
\psline[linewidth=0.085,linecolor=gray](-0.331559,-4.44275)(-1.30238,-3.73741)
\psline[linewidth=0.085,linecolor=gray](-0.653391,-8.01859)(-1.73455,-8.53925)
\psline[linewidth=0.085,linecolor=gray](0.317786,-9.23641)(-0.430402,-10.1746)
\psline[linewidth=0.085,linecolor=gray](1.72118,-9.91225)(1.45415,-11.0822)
\psline[linewidth=0.085,linecolor=gray](3.27882,-9.91225)(3.54585,-11.0822)
\psline[linewidth=0.085,linecolor=gray](4.68221,-9.23641)(5.4304,-10.1746)
\psline[linewidth=0.085,linecolor=gray](5.65339,-8.01859)(6.73455,-8.53925)
\rput(6.62599,-3.5023){${\scriptstyle 1}$}
\rput(4.07599,-1.64961){${\scriptstyle 2}$}
\rput(0.924013,-1.64961){${\scriptstyle 3}$}
\rput(-1.62599,-3.5023){${\scriptstyle 4}$}
\rput(-2.09494,-8.71281){${\scriptstyle 5}$}
\rput(-0.679798,-10.4873){${\scriptstyle 6}$}
\rput(1.36514,-11.4721){${\scriptstyle 7}$}
\rput(3.63486,-11.4721){${\scriptstyle 8}$}
\rput(5.6798,-10.4873){${\scriptstyle 9}$}
\rput(7.09494,-8.71281){${\scriptstyle 10}$}
\psarc[linewidth=0.1,linecolor=black,linestyle=dashed,dash=3pt 2pt](5.49248,-6.23067){1.79515}{-84.8571}{95.1429}
\psline[linewidth=0.1,linecolor=black,linestyle=dashed,dash=3pt 2pt](3.58156,-3.1713)(1.72118,-9.91225)
\psline[linewidth=0.1,linecolor=black,linestyle=dashed,dash=3pt 2pt](1.41844,-3.1713)(0.317786,-9.23641)
\psarc[linewidth=0.1,linecolor=black,linestyle=dashed,dash=3pt 2pt](-0.492475,-6.23067){1.79515}{84.8571}{264.857}
\psarc[linewidth=0.1,linecolor=black,linestyle=dashed,dash=3pt 2pt](3.98052,-9.57433){0.778823}{205.714}{385.714}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](1.41844,-3.1713){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](0.317786,-9.23641){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](4.68221,-9.23641){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](5.33156,-4.44275){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](3.58156,-3.1713){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](-0.331559,-4.44275){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](-0.653391,-8.01859){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](1.72118,-9.91225){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](3.27882,-9.91225){0.3}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black](5.65339,-8.01859){0.3}
\rput[b]{36.}(5.33156,-4.44275){\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](0.85,-0.33)(0.85,0.33)(0.4,0)
}
\rput[b]{72.}(3.58156,-3.1713){\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](0.85,-0.33)(0.85,0.33)(0.4,0)
}
\rput[b]{108.}(1.41844,-3.1713){\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](-0.85,-0.33)(-0.85,0.33)(-0.4,0)
}
\rput[b]{144.}(-0.331559,-4.44275){\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](0.85,-0.33)(0.85,0.33)(0.4,0)
}
\rput[b]{205.714}(-0.653391,-8.01859){\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](-0.85,-0.33)(-0.85,0.33)(-0.4,0)
}
\rput[b]{231.429}(0.317786,-9.23641){\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](0.85,-0.33)(0.85,0.33)(0.4,0)
}
\rput[b]{257.143}(1.72118,-9.91225){\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](-0.85,-0.33)(-0.85,0.33)(-0.4,0)
}
\rput[b]{282.857}(3.27882,-9.91225){\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](-0.85,-0.33)(-0.85,0.33)(-0.4,0)
}
\rput[b]{308.571}(4.68221,-9.23641){\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](0.85,-0.33)(0.85,0.33)(0.4,0)
}
\rput[b]{334.286}(5.65339,-8.01859){\pspolygon[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray](-0.85,-0.33)(-0.85,0.33)(-0.4,0)
}
%
\endpspicture