Problem:
Score : 100 points

Problem Statement

There are S sheep and W wolves.

If the number of wolves is greater than or equal to that of sheep, the wolves will attack the sheep.

If the wolves will attack the sheep, print unsafe; otherwise, print safe.

Constraints

1 \leq S \leq 100

1 \leq W \leq 100

Input

Input is given from Standard Input in the following format:

S W

Output

If the wolves will attack the sheep, print unsafe; otherwise, print safe.

Sample Input 1

4 5

Sample Output 1

unsafe

There are four sheep and five wolves. The number of wolves is not less than that of sheep, so they will attack them.

Sample Input 2

100 2

Sample Output 2

safe

Many a sheep drive away two wolves.

Sample Input 3

10 10

Sample Output 3

unsafe

Solution in C# (.NET Core 3.1.201) (judge verdict: Accepted)

using System;
using System.Collections.Generic;

namespace cswork {
    class Program {
        static void Main (string[] args) {
            // ontest166.Q6 ();
                        List<long> l = ReadList ();
            long s = l[0];
            long w = l[1];

            if (s <= w) {
                Write ("unsafe");
            } else {
                Write ("safe");
            }
            Exit ();
        }

        public static void Write (string str) {
            Console.WriteLine (str);
        }

        public static void Write (int i) {
            Console.WriteLine (i);
        }

        public static void Write (double d) {
            Console.WriteLine (d);
        }

        public static string ReadStr () {
            return Console.ReadLine ();
        }

        public static int ReadInt () {
            return int.Parse (Console.ReadLine ());
        }

        public static long Read () {
            return long.Parse (Console.ReadLine ());
        }

        public static double ReadDouble () {
            return double.Parse (Console.ReadLine ());
        }

        public static void Exit () { }

        public static List<string> ReadListStr () {
            return new List<string> (ReadStr ().Split (" "));
        }

        public static List<long> ReadList () {
            return ReadListStr ().ConvertAll (x => long.Parse (x));
        }
    }
}