(6,9)
\begin{picture}(6,9) \put(3,0){\line(0,1){2}} % input \put(0,2){\line(1,0){6}} \... ...{\line(3,5){3}} \put(3,7){\line(3,-5){3}} \put(3,7){\line(0,1){2}} \end{picture}