#include <bits/stdc++.h>
#pragma GCC optimize("inline")
using namespace std;
const int N = 1e6 + 200;
long long n, k, a[N];
long long modulo(long long a, long long b, long long n) {
  long long x = 1, y = a;
  while (b > 0) {
    if (b % 2 == 1) {
      x = (x * y) % n;
    }
    y = (y * y) % n;
    b /= 2;
  }
  return x % n;
}
map<int, int> m;
int main() {
  cin >> n;
  long long cnt = 0, mm = 0, kk = 0;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    cnt += a[i] - i;
    m[a[i]]++;
    if (m[a[i]] > 2) {
      cout << "cslnb";
      return 0;
    }
    if (m[a[i]] == 2) {
      if (mm) {
        cout << "cslnb";
        return 0;
      }
      if (a[i] == 0) {
        cout << "cslnb";
        return 0;
      }
      mm++;
      kk = a[i];
    }
  }
  if (mm && m[kk - 1]) {
    cout << "cslnb";
    return 0;
  }
  if (cnt % 2 == 0) {
    cout << "cslnb";
    return 0;
  }
  cout << "sjfnb";
  return 0;
}
