import java.util.Scanner;

public class Main{
	public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
		int shp = scan.nextInt();
		int wlf = scan.nextInt();
		String ans = "unsafe";
		
		if(shp > wlf){ans = "safe";}
		
		System.out.println(ans);
	}
} import java.util.Scanner; Scanner java.util public class Main{
	public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
		int shp = scan.nextInt();
		int wlf = scan.nextInt();
		String ans = "unsafe";
		
		if(shp > wlf){ans = "safe";}
		
		System.out.println(ans);
	}
} Main public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
		int shp = scan.nextInt();
		int wlf = scan.nextInt();
		String ans = "unsafe";
		
		if(shp > wlf){ans = "safe";}
		
		System.out.println(ans);
	} main {
		Scanner scan = new Scanner(System.in);
		int shp = scan.nextInt();
		int wlf = scan.nextInt();
		String ans = "unsafe";
		
		if(shp > wlf){ans = "safe";}
		
		System.out.println(ans);
	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) int shp = scan.nextInt(); shp scan.nextInt() scan.nextInt scan int wlf = scan.nextInt(); wlf scan.nextInt() scan.nextInt scan String ans = "unsafe"; ans "unsafe" if(shp > wlf){ans = "safe";} shp > wlf shp wlf {ans = "safe";} ans = "safe" ans "safe" System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main{
	public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
		int shp = scan.nextInt();
		int wlf = scan.nextInt();
		String ans = "unsafe";
		
		if(shp > wlf){ans = "safe";}
		
		System.out.println(ans);
	}
} public class Main{
	public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
		int shp = scan.nextInt();
		int wlf = scan.nextInt();
		String ans = "unsafe";
		
		if(shp > wlf){ans = "safe";}
		
		System.out.println(ans);
	}
} Main
import java.util.Scanner;

public class Main{
	public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
		int shp = scan.nextInt();
		int wlf = scan.nextInt();
		String ans = "unsafe";
		
		if(shp > wlf){ans = "safe";}
		
		System.out.println(ans);
	}
}