#include <bits/stdc++.h>
using namespace std;
int a[10008];
int main() {
  int n, m, k;
  cin >> n >> m >> k;
  for (int i = 1; i <= n; i++) cin >> a[i];
  if (n % 2 == 0) {
    cout << "0";
  } else {
    long long t = (n + 1) / 2;
    t = m / t;
    int kk = 10000008;
    for (int i = 1; i <= n; i += 2) {
      kk = min(a[i], kk);
    }
    if (t * k <= kk)
      cout << (t * k) << endl;
    else
      cout << kk << endl;
  }
}
