#include <bits/stdc++.h>
using namespace std;
const int MAXN = 10000;
const int INF = 1000000000;
long long a[MAXN];
long long n, m, k;
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 maxx = INF;
  for (int i = 0; i < n; i++)
    if (i % 2 == 0) maxx = min(maxx, a[i]);
  long long d = n / 2 + 1;
  long long col = m / d;
  long long res = min(maxx, k * col);
  cout << res << endl;
  return 0;
}
