#include <bits/stdc++.h>
int d[10240];
int main() {
  int n, m, k;
  scanf("%d%d%d", &n, &m, &k);
  for (int i = 0; i < n; i++) scanf("%d", &d[i]);
  long long ans;
  if (n & 1) {
    int need = n / 2 + 1;
    if (m < need)
      ans = 0;
    else {
      ans = d[0];
      for (int i = 0; i < n; i++)
        if ((i & 1) == 0) ans = ((ans) < (d[i]) ? (ans) : (d[i]));
      long long all = (long long)m / need * k;
      ans = ((ans) < (all) ? (ans) : (all));
    }
  } else
    ans = 0;
  printf("%I64d\n", ans);
  return 0;
}
