#include <bits/stdc++.h>
using namespace std;
long long min(long long a, long long b) {
  if (a < b) return a;
  return b;
}
int main() {
  long long i, x, mx, a, ans, k, n, m;
  while (cin >> n >> m >> k) {
    mx = 0xfffffff;
    for (i = 1; i <= n; i++) {
      cin >> a;
      if (i & 1) mx = min(mx, a);
    }
    x = (n + 1) / 2;
    if (n % 2 == 0 || m < x) {
      printf("0\n");
      continue;
    }
    ans = min(mx, k * (m / x));
    cout << ans << endl;
  }
}
