#include <bits/stdc++.h>
using namespace std;
int a[10005];
int n, k, m;
int main() {
  int i, j;
  scanf("%d%d%d", &n, &m, &k);
  for (i = 0; i < n; ++i) scanf("%d", &a[i]);
  if (n % 2 == 0) {
    puts("0");
    return 0;
  }
  if (m < (n + 1) / 2) {
    puts("0");
    return 0;
  }
  long long res = int(1e9);
  for (i = 0; i < n; i += 2) res = min(res, 1LL * a[i]);
  res = min(res, 1LL * k * (m / ((n + 1) / 2)));
  cout << res << endl;
  return 0;
}
