#include <bits/stdc++.h>
using namespace std;
const int MOD = (int)1e9 + 7;
int main() {
  int a, b, c;
  scanf("%d%d%d", &a, &b, &c);
  puts(max(a, max(b, c)) * 2 == a + b + c ? "YES" : "NO");
  return 0;
}
