import java.util.Scanner;


public class Main{
    
      public static int w,s;
      
      public static String isSafe(){
            if(w >= s) return "unsafe";
            return "safe";
      }

       public static void main(String []args){
         Scanner x = new Scanner(System.in);
         s = x.nextInt();
         w = x.nextInt();
         String ans = isSafe();
         System.out.println(ans);
        
      }
} import java.util.Scanner; Scanner java.util public class Main{
    
      public static int w,s;
      
      public static String isSafe(){
            if(w >= s) return "unsafe";
            return "safe";
      }

       public static void main(String []args){
         Scanner x = new Scanner(System.in);
         s = x.nextInt();
         w = x.nextInt();
         String ans = isSafe();
         System.out.println(ans);
        
      }
} Main public static int w w s; s public static String isSafe(){
            if(w >= s) return "unsafe";
            return "safe";
      } isSafe {
            if(w >= s) return "unsafe";
            return "safe";
      } if(w >= s) return "unsafe"; w >= s w s return "unsafe"; "unsafe" return "safe"; "safe" public static void main(String []args){
         Scanner x = new Scanner(System.in);
         s = x.nextInt();
         w = x.nextInt();
         String ans = isSafe();
         System.out.println(ans);
        
      } main {
         Scanner x = new Scanner(System.in);
         s = x.nextInt();
         w = x.nextInt();
         String ans = isSafe();
         System.out.println(ans);
        
      } Scanner x = new Scanner(System.in); x new Scanner(System.in) s = x.nextInt() s x.nextInt() x.nextInt x w = x.nextInt() w x.nextInt() x.nextInt x String ans = isSafe(); ans isSafe() isSafe System.out.println(ans) System.out.println System.out System System.out ans String []args args public class Main{
    
      public static int w,s;
      
      public static String isSafe(){
            if(w >= s) return "unsafe";
            return "safe";
      }

       public static void main(String []args){
         Scanner x = new Scanner(System.in);
         s = x.nextInt();
         w = x.nextInt();
         String ans = isSafe();
         System.out.println(ans);
        
      }
} public class Main{
    
      public static int w,s;
      
      public static String isSafe(){
            if(w >= s) return "unsafe";
            return "safe";
      }

       public static void main(String []args){
         Scanner x = new Scanner(System.in);
         s = x.nextInt();
         w = x.nextInt();
         String ans = isSafe();
         System.out.println(ans);
        
      }
} Main
import java.util.Scanner;


public class Main{
    
      public static int w,s;
      
      public static String isSafe(){
            if(w >= s) return "unsafe";
            return "safe";
      }

       public static void main(String []args){
         Scanner x = new Scanner(System.in);
         s = x.nextInt();
         w = x.nextInt();
         String ans = isSafe();
         System.out.println(ans);
        
      }
}