#include <bits/stdc++.h>
using namespace std;
const long long max_n = 11111, inf = 1111111111;
long long n, m, k, a[max_n];
int main() {
  cin >> n >> m >> k;
  for (int i = 0; i < n; ++i) {
    cin >> a[i];
  }
  if (n % 2 == 0) {
    cout << 0 << endl;
    return 0;
  }
  long long sum = inf;
  for (int i = 0; i < n; i += 2) {
    sum = min(sum, a[i]);
  }
  long long x = (n + 1) / 2;
  x = (m / x) * k;
  cout << min(sum, x) << endl;
  return 0;
}
