#include <bits/stdc++.h>
using namespace std;
const int N = 100010;
inline long long read() {
  long long x = 0;
  bool f = true;
  char c = getchar();
  while (!isdigit(c)) {
    if (c == '-') f = false;
    c = getchar();
  }
  while (isdigit(c)) x = (x << 1) + (x << 3) + (c ^ 48), c = getchar();
  return f ? x : -x;
}
long long n, a[N], sum;
int main() {
  n = read();
  for (register int i = 1; i <= n; ++i) a[i] = read(), sum += a[i] - i + 1;
  std::sort(a + 1, a + n + 1);
  if (!a[min(n, 2ll)]) return puts("cslnb") & 0;
  int cnt = 0;
  for (register int i = 2; i <= n; ++i) {
    if (a[i] == a[i - 1]) {
      if (++cnt >= 2 || ((i >= 3) && (a[i - 2] == a[i - 1] - 1)))
        return puts("cslnb") & 0;
    }
  }
  puts(sum & 1 ? "sjfnb" : "cslnb");
  return 0;
}
