import java.util.Scanner;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        if(sc.nextInt() <= sc.nextInt()){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    }

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

} Main public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        if(sc.nextInt() <= sc.nextInt()){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    } main {
        Scanner sc = new Scanner(System.in);
        if(sc.nextInt() <= sc.nextInt()){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) if(sc.nextInt() <= sc.nextInt()){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        } sc.nextInt() <= sc.nextInt() sc.nextInt() sc.nextInt sc sc.nextInt() sc.nextInt sc {
            System.out.println("unsafe");
        } System.out.println("unsafe") System.out.println System.out System System.out "unsafe" {
            System.out.println("safe");
        } 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){
        Scanner sc = new Scanner(System.in);
        if(sc.nextInt() <= sc.nextInt()){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    }

} public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        if(sc.nextInt() <= sc.nextInt()){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    }

} Main
import java.util.Scanner;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        if(sc.nextInt() <= sc.nextInt()){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    }

}