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

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	int v, t, s, d;
	cin >> v >> t >> s >> d;
	if (v * t <= d && d <= v * s) {
		cout << "No\n";
	} else {
		cout << "Yes\n";
	}
	return 0;
}
#include <bits/stdc++.h>
using namespace std;

int main(){
    int a,b,c;
    cin>>a>>b>>c;
    if(c%2==0){
        a = abs(a);
        b = abs(b);
        if(a>b){
            cout<<">";
            return 0;
        }else if(a==b){
            cout<<"=";
            return 0;
        }else{
            cout<<"<";
            return 0;
        }
    }
    // if i'm here c is odd so now if a>b

    if(a>b){
        cout<<">";
        return 0;
    }else if(a==b){
        cout<<"=";
        return 0;
    }else{
        cout<<"<";
        return 0;
    }
}


