#include <bits/stdc++.h>
using namespace std;
int a[40001];
int main() {
  long long n, m, k;
  while (cin >> n >> m >> k) {
    int j = 0;
    for (; j < n; j++) {
      cin >> a[j];
    }
    if (n % 2 == 0)
      cout << 0 << endl;
    else {
      m /= ((n + 1) / 2);
      if (m == 0)
        cout << 0 << endl;
      else {
        int i = 0;
        int min = a[0];
        for (; i < n; i += 2) {
          if (a[i] < min) {
            min = a[i];
          }
        }
        if (m * k < min) {
          min = m * k;
        }
        cout << min << endl;
      }
    }
  }
  return 0;
}
