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: Runtime Error)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _164C
{
    class Program
    {
        static void Main(string[] args)
        {
            var N = long.Parse(Console.ReadLine());
            string[] S = new string[N];
            long types = 0;
            for (long i = 0; i < N; i++)
            {
                S[i] = Console.ReadLine();
                bool isSameStringContain = false;

                for (long j = 0; j <  i; j++)
                {
                    if (S[i] == S[j])
                    {
                        isSameStringContain = isSameStringContain | true;
                        break;
                    }
                    else
                    {
                        isSameStringContain = isSameStringContain | false;
                    }
                }

                if (!isSameStringContain)
                {
                    types = types + 1;
                }
            }
            
            Console.WriteLine(types);
            
        }
    }
}