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.Diagnostics.Contracts;
using System.Linq;

namespace at_coder
{
#if TEST
    [TestClass]
#endif
    public class Test_164_a
    {

#if TEST
        public static void Test_Main()
#else
        public static void Main()
#endif
        {
            int s, w;
            ReadInt(out s, out w);
            if (w >= s)
            {
                Write("unsafe");
            }
            else
            {
                Write("safe");
            }
        }


        private static void Write(string s)
        {
            Console.WriteLine(s);
        }

        private static int[] ReadIntArray()
        {
            string[] ss = Console.ReadLine().Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
            int[] ar = new int[ss.Length];
            for (int i = 0; i < ss.Length; i++)
            {
                ar[i] = int.Parse(ss[i]);
            }
            return ar;
        }
        private static int ReadInt()
        {
            return int.Parse(Console.ReadLine());
        }
        private static void ReadInt(out int a, out int b)
        {
            var ar = ReadIntArray();
            a = ar[0];
            b = ar[1];
        }
        private static void ReadInt(out int a, out int b, out int c)
        {
            var ar = ReadIntArray();
            a = ar[0];
            b = ar[1];
            c = ar[2];
        }
        private static string ReadString()
        {
            return Console.ReadLine();
        }
        private static string[] ReadStringArray()
        {
            string[] ss = Console.ReadLine().Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
            return ss;
        }
#if !TEST
    }
}
#endif