/* -*- coding: utf-8 -*-
 *
 * 2922.cc:  No.2922 Rose Garden - yukicoder
 */

#include<cstdio>
#include<algorithm>

using namespace std;

/* constant */

const int MAX_N = 200000;

/* typedef */

using ll = long long;

/* global variables */

int hs[MAX_N];

/* subroutines */

/* main */

int main() {
  int n, s, b;
  scanf("%d%d%d", &n, &s, &b);
  for (int i = 0; i < n; i++) scanf("%d", hs + i);

  ll sb = (ll)s * b;
  int ph = hs[0];
  for (int i = 1; i < n; i++)
    if (hs[i] > ph) {
      if (hs[i] > ph + sb) { puts("No"); return 0; }
      ph = hs[i];
    }

  puts("Yes");
  return 0;
}