#include <bits/stdc++.h>
using namespace std;
long long MOD = 1000000007;
long long mod = 998244353;
int inf = 1000001000;
long long INF = 1e18 + 5;
int main() {
  vector<int> a(3);
  cin >> a[0] >> a[1] >> a[2];
  if (a[0] + a[1] == a[2])
    cout << "YES" << endl;
  else
    cout << "NO" << endl;
}
