#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c;
  cin >> a >> b >> c;
  vector<int> v(3);
  v[0] = a;
  v[1] = b;
  v[2] = c;
  sort(v.begin(), v.end());
  if (v[0] + v[1] == v[2]) {
    cout << "yes" << endl;
  } else {
    cout << "no" << endl;
  }
  return 0;
}
