#include <bits/stdc++.h>
using namespace std;
const double PI = 3.14159265;
void fastInOut();
const int OO = (int)2e9;
int main() {
  fastInOut();
  int n, m, k, mn = OO;
  cin >> n >> m >> k;
  for (int i = 0; i < n; i++) {
    int x;
    cin >> x;
    if (i % 2 == 0) mn = min(mn, x);
  }
  if (n % 2 == 0) return cout << 0, 0;
  int x = (n + 1) / 2;
  cout << min(1ll * mn, 1ll * m / x * k);
  return 0;
}
void fastInOut() {
  ios_base::sync_with_stdio(0);
  cin.tie(NULL), cout.tie(NULL);
}
