题解 | #二叉树#

def tree(m,n):  
    if m == n:  
        return 1  
    elif m < n:  
        return tree(2*m, n) + tree(2*m+1, n) + 1  
    else:  
        return 0  
  
li = []  
while True:  
    try:  
        m, n = map(int, input().split())  
  
        if m == 0 and n == 0:  
            break  
        else:  
            print(tree(m, n))  
    except EOFError:  
        # 当读取输入时遇到EOF时，结束循环  
        break