#include <bits/stdc++.h>
using namespace std;
long long n, m, k;
long long x[100001];
int main() {
  ios::sync_with_stdio(false);
  while (cin >> n >> m >> k) {
    for (int i = 1; i <= n; i++) cin >> x[i];
    if (n == 1) {
      cout << min(x[1], m * k) << endl;
    } else if (n % 2 == 0)
      cout << 0 << endl;
    else {
      long long times = m / (n / 2 + 1) * k;
      for (int i = 1; i <= n; i += 2) times = min(times, x[i]);
      cout << times << endl;
    }
  }
  return 0;
}
