汉诺塔

def hano(n,x,y,z):
    if n==1:
        print(x,"-->",z)
    else:
        hano(n-1,x,z,y)
        print(x,"-->",z)
        hano(n-1,y,x,z)
n = int(input(""))
hano(n,"A","B","C")