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# (Mono-mcs 6.8.0.105) (judge verdict: Accepted)

using System;


    class MainClass
    {
    public static void Main(string[] args)
    {
        string[] input = Console.ReadLine().Split(' ');

        int S = int.Parse(input[0]);

        int W = int.Parse(input[1]);

        string result;

        if (S <= W)
        {
            Console.WriteLine("unsafe");

        }
        else
        {
            Console.WriteLine("safe");
        }      
       
    }
}