gistfile1.py

import random

def stumble(size):
    x = int(size / 2)
    y = int(size / 2)
    count = 0
    while -1 < x < size and -1 < y < size:
        x += random.randint(-1, 1)
        y += random.randint(-1, 1)
        count += 1
    return count

def average(list):
    return sum(list) / len(list)

for size in range(1, 50):
    print("Size ", size, ": ", average([stumble(size) for x in range(1000)]))