汉诺塔问题

count=0
def han(n,src,dst,mid):
    global count
    if n==1:
        print("{}:{}->{}".format(1,src,dst))
        count+=1
    else:
        han(n-1,src,mid,dst)
        print("{}:{}->{}".format(n,src,dst))
        count+=1
        han(n-1,mid,dst,src)
han(3,"A","C","B")
print(count)