#include <bits/stdc++.h>
using namespace std;
int n, m, k, a[100005];
void work() {
  int i, x;
  long long ans;
  cin >> n >> m >> k;
  for (i = 1; i <= n; ++i) scanf("%d", &a[i]);
  if (n & 1) {
    m /= (n + 1) >> 1;
    ans = 1LL << 30;
    for (i = 1; i <= n; i += 2) ans = min((long long)a[i], ans);
    ans = min(ans, (long long)m * k);
  } else
    ans = 0;
  cout << ans;
}
int main() {
  work();
  return 0;
}
