import java.util.*;
 
public class Main{
	public static void main(String[] args){
    	Scanner sc = new Scanner(System.in);
		
		System.out.println((sc.nextInt() <= sc.nextInt())?"unsafe":"safe");
		
		sc.close();
    }
} import java.util.*; util.* java public class Main{
	public static void main(String[] args){
    	Scanner sc = new Scanner(System.in);
		
		System.out.println((sc.nextInt() <= sc.nextInt())?"unsafe":"safe");
		
		sc.close();
    }
} Main public static void main(String[] args){
    	Scanner sc = new Scanner(System.in);
		
		System.out.println((sc.nextInt() <= sc.nextInt())?"unsafe":"safe");
		
		sc.close();
    } main {
    	Scanner sc = new Scanner(System.in);
		
		System.out.println((sc.nextInt() <= sc.nextInt())?"unsafe":"safe");
		
		sc.close();
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) System.out.println((sc.nextInt() <= sc.nextInt())?"unsafe":"safe") System.out.println System.out System System.out (sc.nextInt() <= sc.nextInt())?"unsafe":"safe" (sc.nextInt() <= sc.nextInt()) sc.nextInt() sc.nextInt sc sc.nextInt() sc.nextInt sc "unsafe" "safe" sc.close() sc.close sc String[] args args public class Main{
	public static void main(String[] args){
    	Scanner sc = new Scanner(System.in);
		
		System.out.println((sc.nextInt() <= sc.nextInt())?"unsafe":"safe");
		
		sc.close();
    }
} public class Main{
	public static void main(String[] args){
    	Scanner sc = new Scanner(System.in);
		
		System.out.println((sc.nextInt() <= sc.nextInt())?"unsafe":"safe");
		
		sc.close();
    }
} Main
import java.util.*;
 
public class Main{
	public static void main(String[] args){
    	Scanner sc = new Scanner(System.in);
		
		System.out.println((sc.nextInt() <= sc.nextInt())?"unsafe":"safe");
		
		sc.close();
    }
}