#include <bits/stdc++.h>
using namespace std;
int main(){
	long long N, S, B;
	cin >> N >> S >> B;
	vector<long long> H(N);
	for (int i = 0; i < N; i++){
		cin >> H[i];
	}
	bool ok = true;
	for (int i = 0; i < N - 1; i++){
		if (H[i] + S * B < H[i + 1]){
			ok = false;
			break;
		}
	}
	if (ok){
		cout << "Yes" << endl;
	} else {
		cout << "No" << endl;
	}
}