#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, m, k;
  int a[10000];
  cin >> n >> m >> k;
  if (n % 2 == 0) {
    cout << 0;
    return 0;
  }
  for (int i = 0; i < n; i++) {
    scanf("%d", &a[i]);
  }
  if (m < (n + 1) / 2) {
    cout << 0;
    return 0;
  }
  long long res1 = (m / ((n + 1) / 2)) * k, res2 = ((m) / ((n + 1) / 2)) * k;
  for (int i = 0; i < n; i += 2) {
    res2 = min(res2, (long long)a[i]);
  }
  cout << res2;
  return 0;
}
