import java.util.*;
public class Main {
    public static void main(String[] args) {
        int a=0;
        int b=0;

        Scanner scan = new Scanner(System.in);
        int n=scan.nextInt();
        int m=scan.nextInt();
        if(n<=m){
            System.out.println("unsafe");
        }
        else {
            System.out.println("safe");
        }


    }


}
 import java.util.*; util.* java public class Main {
    public static void main(String[] args) {
        int a=0;
        int b=0;

        Scanner scan = new Scanner(System.in);
        int n=scan.nextInt();
        int m=scan.nextInt();
        if(n<=m){
            System.out.println("unsafe");
        }
        else {
            System.out.println("safe");
        }


    }


} Main public static void main(String[] args) {
        int a=0;
        int b=0;

        Scanner scan = new Scanner(System.in);
        int n=scan.nextInt();
        int m=scan.nextInt();
        if(n<=m){
            System.out.println("unsafe");
        }
        else {
            System.out.println("safe");
        }


    } main {
        int a=0;
        int b=0;

        Scanner scan = new Scanner(System.in);
        int n=scan.nextInt();
        int m=scan.nextInt();
        if(n<=m){
            System.out.println("unsafe");
        }
        else {
            System.out.println("safe");
        }


    } int a=0; a 0 int b=0; b 0 Scanner scan = new Scanner(System.in); scan new Scanner(System.in) int n=scan.nextInt(); n scan.nextInt() scan.nextInt scan int m=scan.nextInt(); m scan.nextInt() scan.nextInt scan if(n<=m){
            System.out.println("unsafe");
        }
        else {
            System.out.println("safe");
        } n<=m n m {
            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) {
        int a=0;
        int b=0;

        Scanner scan = new Scanner(System.in);
        int n=scan.nextInt();
        int m=scan.nextInt();
        if(n<=m){
            System.out.println("unsafe");
        }
        else {
            System.out.println("safe");
        }


    }


} public class Main {
    public static void main(String[] args) {
        int a=0;
        int b=0;

        Scanner scan = new Scanner(System.in);
        int n=scan.nextInt();
        int m=scan.nextInt();
        if(n<=m){
            System.out.println("unsafe");
        }
        else {
            System.out.println("safe");
        }


    }


} Main
import java.util.*;
public class Main {
    public static void main(String[] args) {
        int a=0;
        int b=0;

        Scanner scan = new Scanner(System.in);
        int n=scan.nextInt();
        int m=scan.nextInt();
        if(n<=m){
            System.out.println("unsafe");
        }
        else {
            System.out.println("safe");
        }


    }


}

