#include <bits/stdc++.h>
using namespace std;
const long long INF = (long long)1e18;
const int inf = (int)1e9;
const int mod = (int)1e9 + 7;
const int maxn = (int)1e6 + 10;
const double eps = (int)1e-9;
int a[maxn];
int main() {
  int n, m, k;
  cin >> n >> m >> k;
  if (n % 2 == 0) {
    cout << 0 << endl;
    return 0;
  }
  for (int i = 0; i < n; ++i) cin >> a[i];
  int maxAns = inf;
  for (int i = 0; i < n; i += 2) maxAns = min(maxAns, a[i]);
  int cnt = n / 2 + 1;
  long long ans = m * 1ll / cnt * k;
  cout << min(ans, maxAns + 0ll) << endl;
  cerr << (clock() + 0.0) / CLOCKS_PER_SEC << endl;
  return 0;
}
