#include <bits/stdc++.h>
using namespace std;
int n, cnt1, cnt2, b, d;
long long a[100005];
long long sum(long long l, long long r) {
  if (l < 1) l = 1;
  if (r > n) r = n;
  return a[r] - a[l - 1];
}
int main() {
  cin >> n >> d >> b;
  for (int i = 1; i <= n; i++) {
    scanf("%I64d", &a[i]);
    a[i] += a[i - 1];
  }
  for (int i = 1; i <= n / 2; i++) {
    if (sum(1, i + (long long)i * d) >= (long long)(cnt1 + 1) * b) cnt1++;
    if (sum(n - i - (long long)i * d + 1, n) >= (long long)(cnt2 + 1) * b)
      cnt2++;
  }
  cout << max(n / 2 - cnt1, n / 2 - cnt2);
  return 0;
}
