xay loves or
时间限制：C/C++/Rust/Pascal 1秒，其他语言2秒
空间限制：C/C++/Rust/Pascal 256 M，其他语言512 M
64bit IO Format: %lld

题目描述

xay loves or. He gives you x and s, you need to calculate how many positive integer y satisfy .

输入描述:

The first line contains two positive integers x and s .

It's guaranteed that  .

输出描述:

Print the number of y satisfy  .
示例1

输入

复制 
2 5

输出

复制 
0