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