#include <bits/stdc++.h>
using namespace std;
int main(int argc, char** argv) {
  unsigned long long n, m, k;
  cin >> n >> m >> k;
  int* a = new int[n];
  int p = (n + 1) / 2;
  unsigned long long t = 1000000;
  for (int i = 0; i < n; i++) {
    scanf("%d", a + i);
    if (!(i % 2) && a[i] < t) t = a[i];
  }
  if (n % 2 && m >= p) {
    unsigned long long q = m / p;
    cout << min(k * q, t) << endl;
  } else
    cout << 0 << endl;
  return 0;
}
