A. Dasha and Stairs

题目连接：

http://codeforces.com/contest/761/problem/A

Description

On her way to programming school tiger Dasha faced her first test — a huge staircase!

The steps were numbered from one to infinity. As we know, tigers are very fond of all striped things, it is possible that it has something to do with their color. So on some interval of her way she calculated two values — the number of steps with even and odd numbers.

You need to check whether there is an interval of steps from the l-th to the r-th (1 ≤ l ≤ r), for which values that Dasha has found are correct.

Input

In the only line you are given two integers a, b (0 ≤ a, b ≤ 100) — the number of even and odd steps, accordingly.

Output

In the only line print “YES”, if the interval of steps described above exists, and “NO” otherwise.

Sample Input

2 3

Sample Output

YES

Hint

题意

问你在现实生活中，存不存在一个起点和一个终点，使得里面的奇数有a个，偶数有b个。

题解：

1.暴力枚举

2.abs<=1即可，然后特判掉0 0这个数据，这个答案是no

代码

#include<bits/stdc++.h>
using namespace std;

int main()
{
    long long a,b;
    cin>>a>>b;
    for(int l=0;l<=1000;l++){
        for(int r=l;r<=1000;r++){
            int L=0,R=0;
            for(int k=l;k<=r;k++){
                if(k%2==0)R++;
                else L++;
            }
            if(L==a&&R==b){
                cout<<"YES"<<endl;
                return 0;
            }
        }
    }
    cout<<"NO"<<endl;
    return 0;
}