#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e4;
int a[maxn + 10];
int main() {
  long long n, m, k;
  cin >> n >> m >> k;
  for (int i = 0; i < n; ++i) scanf("%d", a + i);
  if (n % 2 == 0)
    cout << "0" << endl;
  else if (m < (n - 1) / 2 + 1)
    cout << "0" << endl;
  else {
    int mina = a[0];
    for (int i = 2; i < n; i += 2)
      if (a[i] < mina) mina = a[i];
    cout << min((long long)mina, k * (m / ((n - 1) / 2 + 1))) << endl;
  }
  return 0;
}
