#include<bits/stdc++.h>
using namespace std;

int main(){
  vector<int> v(4);
  for(int i=0;i<4;i++)
    cin >> v[i];
  
  sort(v.begin(),v.end());
  
  if(v[0]+v[3]==v[1]+v[2])
    cout << "Yes" << endl;
  
  else if(v[0]+v[1]+v[2]==v[3])
    cout << "Yes" << endl;
  
  else
    cout << "No" << endl;
}

#include <bits/stdc++.h>
using namespace std;
int main() {
  int A,B,N;
  cin >> N >> A >> B;

  cout << N - A + B << endl;   

  return 0;
}