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

typedef long long ll;


int main()
{
    int x1, x2, v1, v2;

    cin>> x1 >> v1 >> x2 >> v2;

    if(v2>=v1){
        cout<<"NO"<<endl;
        return 0;
    }

    int n=5;

    vector<int>v;
    int a=x1,b=x2,def=0;
    while(n--){
         a += v1;
         b += v2;
         def = b-a;
         if(def==0){
            cout<<"YES"<<endl;
            return 0;
         }
         v.push_back(def);
    }

    int c = v[0];
    int ans = 0;

    for(int i=0;i<5;i++){
        if(v[i] == c-i)
           ans++;
    }
    (ans==5)?cout<<"YES"<<endl:cout<<"NO"<<endl;

    return 0;

}