#include <bits/stdc++.h>
using namespace std;
const int INF = 1000000000;
const double EPS = 1e-9;
int n;
long long m, k;
long long x[10005];
int main() {
  scanf("%d %lld %lld", &n, &m, &k);
  if (n % 2 == 0) {
    printf("0\n");
    return 0;
  }
  for (int i = 0; i < n; i++) scanf("%lld", &x[i]);
  m /= (n + 1LL) / 2LL;
  long long ans = m * k;
  for (int i = 0; i < n; i++)
    if (i % 2 == 0) ans = min(ans, x[i]);
  printf("%d\n", ans);
  return 0;
}
