#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define all(x) (x).begin(), (x).end()
typedef long long ll;
using namespace std;

int main(void)
{
	ll N, S, B; cin >> N >> S >> B;
	vector<ll> H(N); rep(i, N) cin >> H[i];

	rep(i, N-1)
	{
		if (H[i+1] - H[i] > S * B)
		{
			cout << "No" << endl;
			return 0;
		}
	}
	cout << "Yes" << endl;
	return 0;
}