#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
int main() {
  int n, m, k;
  scanf("%d%d%d", &n, &m, &k);
  vector<int> v(n);
  for (int i = 0; i < n; i++) scanf("%d", &v[i]);
  if (n & 1) {
    int x = min(100000ll, m / ((n + 1) / 2) * 1ll * k);
    for (int i = 0; i < n; i += 2) x = min(x, v[i]);
    printf("%d\n", x);
  } else
    puts("0");
  return 0;
}
