/* package codechef; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
public class Main
{
	public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
		Scanner s=new Scanner(System.in);
		int sh=s.nextInt();
		int w=s.nextInt();
		
		if(w>=sh)
		{
		    System.out.println("unsafe");
		}
		else
		System.out.println("safe");
	}
} import java.util.*; util.* java import java.lang.*; lang.* java import java.io.*; io.* java public class Main
{
	public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
		Scanner s=new Scanner(System.in);
		int sh=s.nextInt();
		int w=s.nextInt();
		
		if(w>=sh)
		{
		    System.out.println("unsafe");
		}
		else
		System.out.println("safe");
	}
} Main public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
		Scanner s=new Scanner(System.in);
		int sh=s.nextInt();
		int w=s.nextInt();
		
		if(w>=sh)
		{
		    System.out.println("unsafe");
		}
		else
		System.out.println("safe");
	} main {
		// your code goes here
		Scanner s=new Scanner(System.in);
		int sh=s.nextInt();
		int w=s.nextInt();
		
		if(w>=sh)
		{
		    System.out.println("unsafe");
		}
		else
		System.out.println("safe");
	} Scanner s=new Scanner(System.in); s new Scanner(System.in) int sh=s.nextInt(); sh s.nextInt() s.nextInt s int w=s.nextInt(); w s.nextInt() s.nextInt s if(w>=sh)
		{
		    System.out.println("unsafe");
		}
		else
		System.out.println("safe"); w>=sh w sh {
		    System.out.println("unsafe");
		} System.out.println("unsafe") System.out.println System.out System System.out "unsafe" System.out.println("safe") System.out.println System.out System System.out "safe" String[] args args public class Main
{
	public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
		Scanner s=new Scanner(System.in);
		int sh=s.nextInt();
		int w=s.nextInt();
		
		if(w>=sh)
		{
		    System.out.println("unsafe");
		}
		else
		System.out.println("safe");
	}
} public class Main
{
	public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
		Scanner s=new Scanner(System.in);
		int sh=s.nextInt();
		int w=s.nextInt();
		
		if(w>=sh)
		{
		    System.out.println("unsafe");
		}
		else
		System.out.println("safe");
	}
} Main
/* package codechef; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
public class Main
{
	public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
		Scanner s=new Scanner(System.in);
		int sh=s.nextInt();
		int w=s.nextInt();
		
		if(w>=sh)
		{
		    System.out.println("unsafe");
		}
		else
		System.out.println("safe");
	}
}
