python -- 汉诺塔问题

def move(x, a, b, c):
    if (x == 1):
        print(a,"->",c)
        return
    move(x-1, a, c, b)
    move(1, a, b, c)
    move(x-1, b, a, c)
n = eval(input())
move(n, "a", "b", "c")