#include <bits/stdc++.h>
int main() {
  int i, n, m, k, a, ans;
  scanf("%d%d%d", &n, &m, &k);
  if (!(n & 1))
    printf("0\n");
  else {
    ans = (((long long)m / ((n + 1) / 2) * k) < (1000000)
               ? ((long long)m / ((n + 1) / 2) * k)
               : (1000000));
    for (i = 1; i <= n; i++) {
      scanf("%d", &a);
      if (i & 1) ans = ((ans) < (a) ? (ans) : (a));
    }
    printf("%d\n", ans);
  }
  return 0;
}
