\psset{unit=0.45cm}
%
\pspicture(-12,-12)(17,9.5)
% 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 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){${\scriptscriptstyle 10}$}
% Coloured/uncoloured starting/ending points
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](-11,0.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](-9,0.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](-8,0.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](-7,0.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](6,0.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](11,0.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](-2,6.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](3,6.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](7,6.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](16,6.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=gray](-4,0.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=gray](-2,0.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=gray](-1,0.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=gray](0,0.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=gray](2,0.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=gray](4,0.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=gray](5,0.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=gray](9,0.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=gray](10,0.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=gray](-6,6.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=gray](-3,6.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=gray](0,6.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=gray](2,6.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=gray](5,6.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=gray](6,6.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=gray](9,6.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=gray](10,6.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=gray](13,6.5){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=gray](14,6.5){0.36}
% Numbering of the coloured points
\rput(16,8.5){\psframebox[fillstyle=solid,fillcolor=white,framearc=0.3]{{\tiny\bf 1}}}
\rput(7,8.5){\psframebox[fillstyle=solid,fillcolor=white,framearc=0.3]{{\tiny\bf 2}}}
\rput(3,8.5){\psframebox[fillstyle=solid,fillcolor=white,framearc=0.3]{{\tiny\bf 3}}}
\rput(-2,8.5){\psframebox[fillstyle=solid,fillcolor=white,framearc=0.3]{{\tiny\bf 4}}}
\rput(-11,-1.5){\psframebox[fillstyle=solid,fillcolor=white,framearc=0.3]{{\tiny\bf 5}}}
\rput(-9,-1.5){\psframebox[fillstyle=solid,fillcolor=white,framearc=0.3]{{\tiny\bf 6}}}
\rput(-8,-1.5){\psframebox[fillstyle=solid,fillcolor=white,framearc=0.3]{{\tiny\bf 7}}}
\rput(-7,-1.5){\psframebox[fillstyle=solid,fillcolor=white,framearc=0.3]{{\tiny\bf 8}}}
\rput(6,-1.5){\psframebox[fillstyle=solid,fillcolor=white,framearc=0.3]{{\tiny\bf 9}}}
\rput(11,-1.5){\psframebox[fillstyle=solid,fillcolor=white,framearc=0.3]{{\tiny\bf 10}}}
\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){${\scriptstyle 10}$}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](5.33156,-4.44275){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](3.58156,-3.1713){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](1.41844,-3.1713){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](-0.331559,-4.44275){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](-0.653391,-8.01859){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](0.317786,-9.23641){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](1.72118,-9.91225){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](3.27882,-9.91225){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](4.68221,-9.23641){0.36}
\pscircle[linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=white](5.65339,-8.01859){0.36}
\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)
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\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)
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\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)
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%
\endpspicture