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;
using System.Diagnostics;
using System.Globalization;
using System.IO.Pipes;
using System.Runtime;

namespace Csharponly
{
    class Program
    {
        static public void Main()
        {
            int[] SW = Arrayint();

            string ans = "unsafe";
            if(SW[0] > SW[1])
            {
                ans = "safe";
            }

            Console.WriteLine(ans);

        }


　　　　//一つの文字列を受け渡す
        static string Onestring()
        {
            return Console.ReadLine();
        }

        //複数の文字列を配列で受け渡す
        //文字列と文字列の間は" "で区切る
        static string[] Arraystring()
        {
            return Console.ReadLine().Split(' ');
        }

        //一つの数字を受け渡す
        static int Oneint()
        {
            return int.Parse(Console.ReadLine());
        }

        //複数の数字を配列で受け渡す
        //数字と数字の間は" "で区切る
        static int[] Arrayint()
        {
            String[] input_line = Console.ReadLine().Split(' ');
            int[] input_num = new int[input_line.Length];
            for (int i = 0; i < input_line.Length; i++)
            {
                input_num[i] = int.Parse(input_line[i]);
            }
            return input_num;
        }
    }
}