#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c;
  cin >> a >> b >> c;
  if ((a + b) == c || (b + c) == a || (c + a) == b) {
    cout << "yes";
  } else {
    cout << "no";
  }
  return 0;
}
