import java.util.Scanner;

class Main {

    public static void main(String[] args) {
        Scanner stdIn=new Scanner(System.in);

        int x=stdIn.nextInt(); //羊
        int y=stdIn.nextInt(); //狼

        if(x>y){
            System.out.println("safe");
            
        }
        else{
            System.out.println("unsafe");
            
        }
        
    }

} import java.util.Scanner; Scanner java.util class Main {

    public static void main(String[] args) {
        Scanner stdIn=new Scanner(System.in);

        int x=stdIn.nextInt(); //羊
        int y=stdIn.nextInt(); //狼

        if(x>y){
            System.out.println("safe");
            
        }
        else{
            System.out.println("unsafe");
            
        }
        
    }

} Main public static void main(String[] args) {
        Scanner stdIn=new Scanner(System.in);

        int x=stdIn.nextInt(); //羊
        int y=stdIn.nextInt(); //狼

        if(x>y){
            System.out.println("safe");
            
        }
        else{
            System.out.println("unsafe");
            
        }
        
    } main {
        Scanner stdIn=new Scanner(System.in);

        int x=stdIn.nextInt(); //羊
        int y=stdIn.nextInt(); //狼

        if(x>y){
            System.out.println("safe");
            
        }
        else{
            System.out.println("unsafe");
            
        }
        
    } Scanner stdIn=new Scanner(System.in); stdIn new Scanner(System.in) int x=stdIn.nextInt(); x stdIn.nextInt() stdIn.nextInt stdIn int y=stdIn.nextInt(); y stdIn.nextInt() stdIn.nextInt stdIn if(x>y){
            System.out.println("safe");
            
        }
        else{
            System.out.println("unsafe");
            
        } x>y x y {
            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
import java.util.Scanner;

class Main {

    public static void main(String[] args) {
        Scanner stdIn=new Scanner(System.in);

        int x=stdIn.nextInt(); //羊
        int y=stdIn.nextInt(); //狼

        if(x>y){
            System.out.println("safe");
            
        }
        else{
            System.out.println("unsafe");
            
        }
        
    }

}