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

int main(){
  vector<int> x(4);
  for(int i = 0; i < 4; i++) cin >> x[i];
  sort(x.begin(), x.end());
  bool ans = false;
  do{
    if(x[0] + 1 == x[1] && x[0] + 2 == x[2] && x[0] + 3 == x[3]){
      ans = true;
    }
  }while(next_permutation(x.begin(), x.end()));
  if(ans) cout << "Yes" << endl;
  else cout << "No" << endl;
}