#include <bits/stdc++.h>
using namespace std;
int n, m, k;
int a[10010];
int main() {
  scanf("%d%d%d", &n, &m, &k);
  if (n % 2 == 0 || m < (n + 1) / 2) {
    printf("0\n");
    return 0;
  }
  for (int i = 0; i < n; i++) {
    scanf("%d", &a[i]);
    if (i % 2 == 0) a[0] = min(a[0], a[i]);
  }
  int t = m / ((n + 1) / 2);
  printf("%d\n", min((long long)a[0], (long long)k * t));
}
