#include <bits/stdc++.h>
using namespace std;
vector<long long> a;
long long n, m, k, i, ans;
int main() {
  scanf("%I64d%I64d%I64d", &n, &m, &k);
  a.resize(n);
  for (i = 0; i < n; i++) scanf("%d", &a[i]);
  if (!(n & 1))
    printf("0\n");
  else {
    ans = k * floor(1.0 * m / ((n + 1) / 2));
    for (i = 0; i < n; i += 2) ans = min(ans, a[i]);
    printf("%I64d\n", ans);
  }
  return 0;
}
