#include <bits/stdc++.h>

using namespace std;
using ll = long long;

int main(){
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);

    ll N, S, B, H, mx;
    cin >> N >> S >> B;
    cin >> H;
    mx = H;
    for (int i=2; i<=N; i++){
        cin >> H;
        if (H > mx + B*S){
            cout << "No" << endl;
            return 0;
        }
        mx = max(mx, H);
    }
    cout << "Yes" << endl;

    return 0;
}