\documentclass[../main.tex]{subfiles} \begin{document} \problem{One Hundred and Forty-Five Doors} A prisoner was thrown into a medieval dungeon with 145 doors. Nine, shown by black bars, are locked, but each one will open if before you reach it you pass through exactly 8 open doors. \\ You don't have to go through every open door but you do have to go through every cell and all 9 locked doors. If you enter a cell or go through a door a second time, the doors clang shut, trapping you. \\ \medskip The prisoner (in the lower right corner cell) had a drawing of the dungeon. He thought a long time before he set out. He went through all the locked doors and escaped through the last, upper left corner one. What was his route? \begin{figure}[h] \centering \includegraphics[width=8cm]{120} \end{figure} \begin{figure}[h] \centering \includegraphics[width=8cm]{120} \end{figure} \end{document}