#include <bits/stdc++.h>
using namespace std;
const int M = 10000 + 10;
int a[M];
int main() {
  long long int n, m, k;
  cin >> n >> m >> k;
  long long int min_v = 1E+9;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    if (i % 2 == 1 && a[i] < min_v) {
      min_v = a[i];
    }
  }
  if (n % 2 == 0) {
    cout << "0" << endl;
  } else {
    long long int x = 2 * m / (n + 1);
    long long int y = x * k;
    long long int ans = (y > min_v ? min_v : y);
    cout << ans << endl;
  }
  return 0;
}
