#include <bits/stdc++.h>
using namespace std;
int const N = 5e5 + 10;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int n = 4, aa[4], sum = 0;
  for (int i = 0; i < n; i++) cin >> aa[i], sum += aa[i];
  if (sum % 2) {
    cout << "No\n";
    return 0;
  }
  if (aa[0] + aa[1] == sum / 2 || aa[0] + aa[2] == sum / 2 ||
      aa[0] + aa[3] == sum / 2 || aa[0] == sum / 2 || aa[1] == sum / 2 ||
      aa[2] == sum / 2 || aa[3] == sum / 2)
    cout << "Yes";
  else
    cout << "No";
  return 0;
}
