#include <bits/stdc++.h>
using namespace std;
const int MAX = 10010;
long long n, m, k;
long long a[MAX];
int main() {
  cin >> n >> m >> k;
  for (int i = 0; i < n; ++i) cin >> a[i];
  if (n % 2 == 0) {
    cout << 0;
    return 0;
  }
  if (n % 2 == 1) {
    long long t = n / 2 + 1;
    long long step = m / t;
    if (step == 0) {
      cout << 0;
      return 0;
    }
    long long ans = step * k;
    for (int i = 0; i < n; i += 2) ans = min(ans, a[i]);
    cout << ans;
  }
  return 0;
}
