#include <iostream>
using namespace std;
const double EPS = 1e-9; //小数点位数太多，直接进行判断会死
int main() {
    double a,b,c;
    cin>>a>>b>>c;
    if(abs(a - b - c) < EPS) cout<<"YES";  //加法换成减法
    else cout<<"NO";
    return 0;
}