#include <bits/stdc++.h>
using namespace std;
int n;
long long m, k;
int arr[10001];
int main() {
  while (cin >> n >> m >> k) {
    long long mn = 1000000;
    for (int i = 0; i < n; i++) {
      cin >> arr[i];
      if (i % 2 == 0) mn = min(mn, (long long)arr[i]);
    }
    if (n % 2 == 0) {
      cout << 0 << endl;
      continue;
    }
    long long tmp = k * (m / (n / 2 + 1));
    cout << min(tmp, mn) << endl;
  }
  return 0;
}
