#include <bits/stdc++.h>
using namespace std;
long long N, M, K, A[100005];
int main() {
  cin >> N >> M >> K;
  long long lo = 1e9;
  for (int i = 0; i < N; i++) {
    cin >> A[i];
    if (i % 2 == 0) {
      lo = min(lo, A[i]);
    }
  }
  if (N % 2 == 0) {
    cout << "0\n";
    return 0;
  }
  long long res = lo;
  res = min(res, K * (M / (N / 2 + 1)));
  cout << res << endl;
}
