#include <bits/stdc++.h>
using namespace std;
int32_t main() {
  long long int n, i, k, ans = -1, x, l, sum;
  cin >> n;
  long long int a[n + 2];
  a[0] = 0;
  long long int ca[n + 2];
  ca[0] = 0;
  l = (n + 1) / 2;
  for (i = 1; i <= n; i++) {
    if (i <= l) {
      cin >> a[i];
    } else {
      a[i] = x;
    }
    ca[i] = ca[i - 1] + a[i];
    if (i == l) cin >> x;
  }
  long long int mn[n + 2];
  mn[0] = 0;
  for (i = 1; i <= l; i++) {
    sum = i * x - ca[i];
    mn[i] = min(mn[i - 1], sum);
  }
  for (i = l; i <= n; i++) {
    sum = ca[i];
    k = n - i;
    sum += mn[k];
    if (sum > 0) {
      ans = i;
    }
  }
  cout << ans;
  return 0;
}
