#include <bits/stdc++.h>
using namespace std;
long long n, k, m, val[10005];
int main() {
  cin >> n >> m >> k;
  for (int i = 0; i < (n); i++) cin >> val[i];
  if (n % 2 == 0)
    cout << 0 << endl;
  else {
    if (n == 1)
      cout << ((val[0]) < (m * k) ? (val[0]) : (m * k)) << endl;
    else {
      if (m < (n / 2 + 1))
        cout << 0 << endl;
      else {
        long long b = val[0];
        for (int i = 2; i < n; i += 2) b = ((b) < (val[i]) ? (b) : (val[i]));
        b = ((b) < ((m / (n / 2 + 1)) * k) ? (b) : ((m / (n / 2 + 1)) * k));
        cout << b << endl;
      }
    }
  }
  return 0;
}
