#include <bits/stdc++.h>
using namespace std;
const int N = 1e4 + 5;
int n, a[N], m, k;
long long ans;
int main() {
  scanf("%d%d%d", &n, &m, &k);
  for (int i = 1; i <= n; i++) scanf("%d", &a[i]);
  if (n % 2 == 0) {
    puts("0");
    return 0;
  }
  int mn = N * 100;
  for (int i = 1; i <= n; i += 2) mn = min(mn, a[i]);
  long long ans = min((long long)mn, 1ll * (m / ((n + 1) / 2)) * k);
  cout << ans;
  return 0;
}
