#include <bits/stdc++.h>
using namespace std;
const long long INF = 0x7fffffffffffffff;
const int MAXN = 1e4;
long long a[MAXN + 5];
int main() {
  long long n, m, k;
  cin >> n >> m >> k;
  long long minnum = INF;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    if (i % 2 == 1) {
      minnum = min(minnum, a[i]);
    }
  }
  if (n % 2 == 0 || n / 2 + 1 > m) {
    cout << 0;
  } else {
    cout << min(minnum, (m / (n / 2 + 1)) * k);
  }
  return 0;
}
