#include <bits/stdc++.h>
using namespace std;
int main() {
  vector<int> A(3);
  cin >> A.at(0) >> A.at(1) >> A.at(2);
  if (1 <= A.at(0) && A.at(0) <= 100 && 1 <= A.at(1) && A.at(1) <= 100 &&
      1 <= A.at(2) && A.at(2) <= 100) {
    sort(A.begin(), A.end());
    if (A.at(0) + A.at(1) == A.at(2)) {
      std::cout << "yes" << std::endl;
    } else {
      std::cout << "no" << std::endl;
    }
    return 0;
  }
}
