"Simule une marche et retourne son résultat"
def robtom4_0():
    from random import sample
    x, y = 0, 0
    urne = {-1, 0, 1}
    while y <= 1 and y >= -1 and x <= 9:
        n = sample(urne, 1)
        y = y + n[0]
        x = x + 1
    if y == -2 or y == 2:
        passage = 0
    else:
        passage = 1
    return(passage)