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