#include <bits/stdc++.h>
using namespace std;
int main() {
  int i, j, n, m, min, step, t, x;
  long long k, ans;
  while (cin >> n >> m >> k) {
    if (n % 2 == 0) {
      for (i = 0; i < n; i++) cin >> x;
      cout << 0 << endl;
      continue;
    }
    if (n == 1) {
      cin >> ans;
      if (m * k < ans) ans = m * k;
      cout << ans << endl;
      continue;
    }
    step = m / ((n + 1) / 2);
    cin >> min;
    for (i = (n - 1) / 2; i > 0; i--) {
      cin >> t >> x;
      if (x < min) min = x;
    }
    if (step * k > min)
      ans = min;
    else
      ans = step * k;
    cout << ans << endl;
  }
}
