#include <bits/stdc++.h>
using namespace std;
int a[1000005];
long long n, m, k, t, x;
int main() {
  cin >> n >> m >> k;
  for (int i = 1; i <= n; ++i) scanf("%d", &a[i]);
  if (n % 2 == 0) {
    puts("0");
    return 0;
  }
  x = 2000000;
  for (int i = 1; i <= n; i += 2) x = min(x, (long long)a[i]);
  t = n / 2 + 1;
  if (t > m) {
    puts("0");
    return 0;
  }
  cout << min(m / t * k, x) << endl;
  return 0;
}
