#include <bits/stdc++.h>
using namespace std;
const int maxn = 10005;
int a[maxn];
int main() {
  int n, m, k;
  while (~scanf("%d %d %d", &n, &m, &k)) {
    for (int i = 1; i <= n; i++) scanf("%d", &a[i]);
    int sum = 10000000;
    for (int i = 1; i <= n; i++)
      if (i % 2 == 1) sum = min(sum, a[i]);
    int ans = (n + 1) / 2;
    if (sum == 0 || m < ans || n % 2 == 0) {
      printf("0\n");
      continue;
    }
    long long t = m / ans;
    t *= k;
    if (n == 1) {
      long long tt = (long long)m * k;
      if (a[1] > tt) a[1] = tt;
      cout << a[1] << endl;
    } else {
      if (sum > t) sum = t;
      printf("%d\n", sum);
    }
  }
  return 0;
}
