#include <bits/stdc++.h>
using namespace std;
const double pi = acos(-1.0);
const double eps = 1e-11;
const int inf = 0x7FFFFFFF;
template <class T>
inline void checkmin(T &a, T b) {
  if (b < a) a = b;
}
template <class T>
inline void checkmax(T &a, T b) {
  if (b > a) a = b;
}
template <class T>
inline T sqr(T x) {
  return x * x;
}
template <class T>
void show(T a, int n) {
  for (int i = 0; i < n; ++i) cout << a[i] << ' ';
  cout << endl;
}
template <class T>
void show(T a, int r, int l) {
  for (int i = 0; i < r; ++i) show(a[i], l);
  cout << endl;
}
int a[100005];
int main() {
  int n, m, k;
  while (cin >> n >> m >> k) {
    for (int i = 0; i < n; i++) cin >> a[i];
    if (n % 2 == 0) {
      cout << 0 << endl;
      continue;
    }
    long long ans = inf;
    for (int i = 0; i < n; i += 2)
      if (ans > a[i]) ans = a[i];
    long long tans = m / ((n + 1) / 2) * (long long)k;
    if (ans > tans) ans = tans;
    cout << ans << endl;
  }
  return 0;
}
