#include <bits/stdc++.h>
using namespace std;
const int maxn = 20000 + 5;
int a[maxn];
long long solve(long long n, long long m, long long k, int a[]) {
  if (n % 2 == 0) return 0;
  int mm = 1000000000 * 2;
  for (int i = 0; i < n; i += 2) {
    mm = min(mm, a[i]);
  }
  long long t = (n + 1) / 2;
  mm = min<long long>(mm, m / t * k);
  return mm;
}
int main() {
  long long n, m, k;
  while (cin >> n >> m >> k) {
    for (int i = 0; i < n; ++i) {
      scanf("%d", &a[i]);
    }
    cout << solve(n, m, k, a) << endl;
    ;
  }
}
