#include <bits/stdc++.h>
using namespace std;
int main() 
{
    int a[4];
    for(int i=0;i<4;i++)
    cin>>a[i];

sort(a, a + 4);

  if (a[0] + a[3] == a[1] + a[2] || a[0] + a[1] + a[2] == a[3])
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
 

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

int main(){
    int v,t,s,d;
    cin >> v >> t >> s >> d;
    cout << ((d < v * t || d > v * s)?"Yes":"No");
}