#include <bits/stdc++.h>
using namespace std;
long long a[100010];
map<long long, int> M;
int main() {
  long long n;
  scanf("%lld", &n);
  long long sum = -n * (n - 1) / 2;
  for (int i = 1; i <= n; ++i) scanf("%lld", &a[i]), ++M[a[i]], sum += a[i];
  int f = 0, two = 0;
  for (auto A : M) {
    long long now = A.first;
    if (M[now] >= 3) f = 1;
    if (M[now] >= 2) ++two;
    if (M[now] >= 2 && M[now - 1] >= 1) f = 1;
  }
  if (M[0] >= 2 || two >= 2) f = 1;
  if (sum % 2 == 0) f = 1;
  if (!f)
    puts("sjfnb");
  else
    puts("cslnb");
  return 0;
}
