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

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    
    ll n,s,b;
    cin >> n >> s >> b;
    vector<int> h(n);
    rep(i,n) cin >> h[i];

    rep(i,n-1){
        if(h[i]+s*b<h[i+1]) {
            cout << "No" << endl;
            return 0;
        }
    }
    cout << "Yes" << endl;
}