import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int hituzi = sc.nextInt();
        int ookami = sc.nextInt();
        if(ookami >= hituzi){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int hituzi = sc.nextInt();
        int ookami = sc.nextInt();
        if(ookami >= hituzi){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    }
} Main public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int hituzi = sc.nextInt();
        int ookami = sc.nextInt();
        if(ookami >= hituzi){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    } main {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int hituzi = sc.nextInt();
        int ookami = sc.nextInt();
        if(ookami >= hituzi){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int hituzi = sc.nextInt(); hituzi sc.nextInt() sc.nextInt sc int ookami = sc.nextInt(); ookami sc.nextInt() sc.nextInt sc if(ookami >= hituzi){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        } ookami >= hituzi ookami hituzi {
            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) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int hituzi = sc.nextInt();
        int ookami = sc.nextInt();
        if(ookami >= hituzi){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int hituzi = sc.nextInt();
        int ookami = sc.nextInt();
        if(ookami >= hituzi){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int hituzi = sc.nextInt();
        int ookami = sc.nextInt();
        if(ookami >= hituzi){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    }
}
