#include <bits/stdc++.h>
using namespace std;
int main() {
  for (long long int a, b, c, s1, s2, x1, x2; cin >> a >> c >> b;) {
    cin >> x1;
    for (int i = 2; i <= a && cin >> x2; ++i) {
      if (i % 2 == 1 && x2 < x1) x1 = x2;
    }
    if (a % 2 == 0) {
      cout << 0 << endl;
      continue;
    }
    s1 = x1;
    s2 = b * (c / ((a + 1) / 2));
    printf("%lld\n", (s1 > s2 ? s2 : s1));
  }
}
