题目描述

Mr Aoligei participates in a programming contest. The full marks of the programming contest is \(m\). Now, he has \(n\) marks. Because his \(IQ\) is too low, he does not know how many marks he needs to gain to reach full marks. Actually, he cannot reach full marks because his \(IQ\) is too low.

输入格式

Input is given from Standard Input in the following format:

\[{\large{m\space \space n}}\]

限制

• \(0 \leq n < m \leq 10^9\)

输出格式

Print the mark he needs to gain to reach full marks.

输入输出样例

Input #1

100 98

Output #1

2