#include <bits/stdc++.h>
using namespace std;
long long n, d, b;
long long a[100005], luse, ruse;
long long sum(long long l, long long r) {
  return a[min(r, n)] - a[max(l - 1, 0LL)];
}
int main() {
  ios_base::sync_with_stdio(false);
  cout.setf(ios::fixed);
  cout.precision(20);
  cout.tie(nullptr);
  cin.tie(nullptr);
  ;
  cin >> n >> d >> b;
  for (int i = 1; i <= n; ++i) {
    cin >> a[i];
    a[i] += a[i - 1];
  }
  for (long long i = 1; i <= n / 2; ++i) {
    if (sum(1, i * (d + 1)) >= (luse + 1) * b) ++luse;
    if (sum(n - i * (d + 1) + 1, n) >= (ruse + 1) * b) ++ruse;
  }
  cout << max(n / 2 - luse, n / 2 - ruse) << endl;
}
