Motion in a straight line

A drunkard walking in a narrow lane takes 5 steps forward and 3 steps backward,
followed again by 5 steps forward and 3 steps backward, and so on. Each step is 1 m
long and requires 1 s. Plot the x-t graph of his motion. Determine graphically and
otherwise how long the drunkard takes to fall in a pit 13 m away from the start.