#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int a, b, c;
  string flag = "NO";
  cin >> a >> b >> c;
  if (a + b == c)
    flag = "YES";
  else if (abs(a - b) == c)
    flag = "YES";
  cout << flag << endl;
}
