#include <bits/stdc++.h>
using namespace std;
long long d[1000 * 11];
int main() {
  long long n, m, k;
  cin >> n >> m >> k;
  for (int i = 0; i < n; i++) cin >> d[i];
  if (n == 1) {
    long long te = k * m;
    cout << min(te, d[0]);
    return 0;
  }
  if (m == 1) {
    cout << 0;
    return 0;
  }
  if (n % 2 == 0) {
    cout << 0;
    return 0;
  }
  long long qp = n / 2 + 1;
  long long h = m / qp;
  long long ans = h * 1ll * k;
  long long minx = d[0];
  for (int i = 2; i < n; i += 2) minx = min(d[i], minx);
  ans = min(ans, minx);
  cout << ans;
  return 0;
}
