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