#include <bits/stdc++.h>
using namespace std;
const double EPS = 1e-12;
const int INF = 999999999;
const int kMaxN = 10000;
int n, m, k;
int a[kMaxN];
int Solve() {
  if (n % 2 == 0) return 0;
  int p = n / 2 + 1;
  int times = m / p;
  if (times == 0) return 0;
  long long res = (long long)times * k;
  for (int i = 0; i < n; i += 2)
    if (a[i] < res) res = a[i];
  return (int)res;
}
int main() {
  scanf("%d%d%d", &n, &m, &k);
  for (int i = 0; i < n; ++i) scanf("%d", &a[i]);
  printf("%d\n", Solve());
  return 0;
}
