#include <bits/stdc++.h>
using namespace std;
inline void FAST_IO() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
}
template <class F, class S>
ostream& operator<<(ostream& os, pair<F, S>& p) {
  os << "(" << p.first << "," << p.second << ")";
  return os;
}
template <class T>
ostream& operator<<(ostream& os, set<T>& v) {
  os << "(";
  for (auto& i : v) cout << i << ",";
  os << ")";
  return os;
}
template <class T>
ostream& operator<<(ostream& os, vector<T>& v) {
  os << "(";
  if (v.size()) os << v[0];
  for (int i = 1; i < v.size(); ++i) os << "," << v[i];
  os << ")";
  return os;
}
int main() {
  long long n, m, k;
  cin >> n >> m >> k;
  vector<int> a(n);
  for (auto& v : a) cin >> v;
  int base = ~(1 << 31);
  for (int i = 0; i < n; i += 2) base = min(base, a[i]);
  if (a.size() % 2 == 0)
    cout << 0 << endl;
  else
    cout << min((long long)base, k * (m / ((n + 1) / 2))) << endl;
  return 0;
}
