import java.util.Scanner;

public class Main {
    public static void main(String[] args) throws Exception {

        Scanner scan = new Scanner(System.in);
        
		String[] str = scan.nextLine().split(" ");
		int[] x = new int[str.length];
		
        for(int i = 0; i < str.length; i++){
            x[i] = Integer.parseInt(str[i]);
        }
        
        if(x[0] > x[1]){
            System.out.println("safe");
        }else{
            System.out.println("unsafe");
        }
        
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) throws Exception {

        Scanner scan = new Scanner(System.in);
        
		String[] str = scan.nextLine().split(" ");
		int[] x = new int[str.length];
		
        for(int i = 0; i < str.length; i++){
            x[i] = Integer.parseInt(str[i]);
        }
        
        if(x[0] > x[1]){
            System.out.println("safe");
        }else{
            System.out.println("unsafe");
        }
        
    }
} Main public static void main(String[] args) throws Exception {

        Scanner scan = new Scanner(System.in);
        
		String[] str = scan.nextLine().split(" ");
		int[] x = new int[str.length];
		
        for(int i = 0; i < str.length; i++){
            x[i] = Integer.parseInt(str[i]);
        }
        
        if(x[0] > x[1]){
            System.out.println("safe");
        }else{
            System.out.println("unsafe");
        }
        
    } main {

        Scanner scan = new Scanner(System.in);
        
		String[] str = scan.nextLine().split(" ");
		int[] x = new int[str.length];
		
        for(int i = 0; i < str.length; i++){
            x[i] = Integer.parseInt(str[i]);
        }
        
        if(x[0] > x[1]){
            System.out.println("safe");
        }else{
            System.out.println("unsafe");
        }
        
    } Scanner scan = new Scanner(System.in); scan new Scanner(System.in) String[] str = scan.nextLine().split(" "); str scan.nextLine().split(" ") scan.nextLine().split scan.nextLine() scan.nextLine scan " " int[] x = new int[str.length]; x new int[str.length] str.length str str.length for(int i = 0; i < str.length; i++){
            x[i] = Integer.parseInt(str[i]);
        } int i = 0; int i = 0; i 0 i < str.length i str.length str str.length i++ i++ i {
            x[i] = Integer.parseInt(str[i]);
        } {
            x[i] = Integer.parseInt(str[i]);
        } x[i] = Integer.parseInt(str[i]) x[i] x i Integer.parseInt(str[i]) Integer.parseInt Integer str[i] str i if(x[0] > x[1]){
            System.out.println("safe");
        }else{
            System.out.println("unsafe");
        } x[0] > x[1] x[0] x 0 x[1] x 1 {
            System.out.println("safe");
        } System.out.println("safe") System.out.println System.out System System.out "safe" {
            System.out.println("unsafe");
        } System.out.println("unsafe") System.out.println System.out System System.out "unsafe" String[] args args public class Main {
    public static void main(String[] args) throws Exception {

        Scanner scan = new Scanner(System.in);
        
		String[] str = scan.nextLine().split(" ");
		int[] x = new int[str.length];
		
        for(int i = 0; i < str.length; i++){
            x[i] = Integer.parseInt(str[i]);
        }
        
        if(x[0] > x[1]){
            System.out.println("safe");
        }else{
            System.out.println("unsafe");
        }
        
    }
} public class Main {
    public static void main(String[] args) throws Exception {

        Scanner scan = new Scanner(System.in);
        
		String[] str = scan.nextLine().split(" ");
		int[] x = new int[str.length];
		
        for(int i = 0; i < str.length; i++){
            x[i] = Integer.parseInt(str[i]);
        }
        
        if(x[0] > x[1]){
            System.out.println("safe");
        }else{
            System.out.println("unsafe");
        }
        
    }
} Main
import java.util.Scanner;

public class Main {
    public static void main(String[] args) throws Exception {

        Scanner scan = new Scanner(System.in);
        
		String[] str = scan.nextLine().split(" ");
		int[] x = new int[str.length];
		
        for(int i = 0; i < str.length; i++){
            x[i] = Integer.parseInt(str[i]);
        }
        
        if(x[0] > x[1]){
            System.out.println("safe");
        }else{
            System.out.println("unsafe");
        }
        
    }
}