#include <bits/stdc++.h>
using namespace std;
int a[100011];
pair<int, int> p[100011];
int main() {
  int n, m, k;
  cin >> n >> m >> k;
  if (n % 2 == 0) {
    cout << 0;
    return 0;
  }
  int a[100000];
  for (int i = 0; i < (int)(n); i++) cin >> a[i];
  int mn = (int)1e9;
  for (int i = 0; i < n; i += 2) mn = min(mn, a[i]);
  unsigned long long ans = k * (m / ((n + 1) / 2));
  if (ans > (unsigned long long)mn)
    cout << mn;
  else
    cout << ans;
  return 0;
}
