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.Text;
using System.Collections.Generic;
using static System.Math;
using System.Linq;
using static System.Array;

namespace ConsoleApp2
{
    class Program
    {
        static int N;
        static int[] zurashi;
        static string S;
        static void Main(string[] args)
        {
            var inp = Console.ReadLine().Split(' ').Select(x => long.Parse(x)).ToArray();
            
            if(inp[0] <= inp[1]){
              Console.WriteLine("unsafe");
            }else{
              Console.WriteLine("safe");
            }
           
            
        }

        static void MakeZurashi(int i)
        {
            var len = N - i;
            zurashi = new int[len];
            var count = 0;

            for (int j = 1; j < len; j++)
            {
                zurashi[j] = count;
                if (S[count] == S[j])
                {
                    count++;
                }
                else
                {
                    count = 0;
                }
            }
        }
    }
}