#include <bits/stdc++.h>
using namespace std;
template <class TT>
TT abs(TT a) {
  if (a < 0) return -a;
  return a;
}
long long a[111111], d[111111];
int main() {
  long long i, j, k, l, n, m, ad, an, g, sum, mi;
  while (cin >> n >> m >> k) {
    i = 0;
    scanf("%I64d", a + i);
    mi = a[0];
    for (i = 1; i < n; i++) {
      scanf("%I64d", a + i);
      sum += a[i];
      if (i % 2 == 0) {
        mi = min(mi, a[i]);
      }
    }
    if (n == 1) {
      cout << min(a[0], k * m) << endl;
      continue;
    } else if (n % 2 == 0) {
      cout << 0 << endl;
      continue;
    }
    n++;
    n /= 2;
    m /= n;
    k *= m;
    cout << min(k, mi) << endl;
  }
  return 0;
}
