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


int main(){
  int a,b,c,d;
  cin >> a >> b >> c >> d;
  int tot=a+b+c+d;
  int ok=0;
  if(tot-a==a)ok=1;
  if(tot-b==b)ok=1;
  if(tot-c==c)ok=1;
  if(tot-d==d)ok=1;
  if(tot-a-b==a+b)ok=1;
  if(tot-a-c==a+c)ok=1;
  if(tot-a-d==a+d)ok=1;
  if(tot-b-c==c+b)ok=1;
  if(tot-b-d==d+b)ok=1;
  if(tot-d-c==c+d)ok=1;

  if(ok)cout << "Yes" << endl;
  else cout << "No" << endl;
  return 0;
}

#include<bits/stdc++.h>
#include <math.h>
using namespace std;
using ll = long long;
const double pi=acos(-1.0);
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

int max(int a,int b){if(a>b){return a;}return b;}
int min(int a,int b){if(a<b){return a;}return b;}
int main(void){
    long long int a,n,v,t,s,d;
    cin>>v>>t>>s>>d;
    if(v*t<=d&&d<=v*s){cout<<"No"<<endl; return 0;}
    cout<<"Yes"<<endl;
    
    
    
}