#include <bits/stdc++.h>
using namespace std;
int main() {
  vector<int> A(3);
  cin >> A.at(0) >> A.at(1) >> A.at(2);
  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;
}
