import java.util.*;
 
public class Main { //クラス名はMain
    public static void main(String[] args) {
      //整数の入力
      Scanner sc = new Scanner(System.in);
      int S = Integer.parseInt(sc.next());
      int W = Integer.parseInt(sc.next());
      
      String kotae = S <= W ? "unsafe" : "safe";
      System.out.println(kotae);
    }  
} import java.util.*; util.* java public class Main { //クラス名はMain
    public static void main(String[] args) {
      //整数の入力
      Scanner sc = new Scanner(System.in);
      int S = Integer.parseInt(sc.next());
      int W = Integer.parseInt(sc.next());
      
      String kotae = S <= W ? "unsafe" : "safe";
      System.out.println(kotae);
    }  
} Main public static void main(String[] args) {
      //整数の入力
      Scanner sc = new Scanner(System.in);
      int S = Integer.parseInt(sc.next());
      int W = Integer.parseInt(sc.next());
      
      String kotae = S <= W ? "unsafe" : "safe";
      System.out.println(kotae);
    } main {
      //整数の入力
      Scanner sc = new Scanner(System.in);
      int S = Integer.parseInt(sc.next());
      int W = Integer.parseInt(sc.next());
      
      String kotae = S <= W ? "unsafe" : "safe";
      System.out.println(kotae);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int S = Integer.parseInt(sc.next()); S Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc int W = Integer.parseInt(sc.next()); W Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc String kotae = S <= W ? "unsafe" : "safe"; kotae S <= W ? "unsafe" : "safe" S <= W S W "unsafe" "safe" System.out.println(kotae) System.out.println System.out System System.out kotae String[] args args public class Main { //クラス名はMain
    public static void main(String[] args) {
      //整数の入力
      Scanner sc = new Scanner(System.in);
      int S = Integer.parseInt(sc.next());
      int W = Integer.parseInt(sc.next());
      
      String kotae = S <= W ? "unsafe" : "safe";
      System.out.println(kotae);
    }  
} public class Main { //クラス名はMain
    public static void main(String[] args) {
      //整数の入力
      Scanner sc = new Scanner(System.in);
      int S = Integer.parseInt(sc.next());
      int W = Integer.parseInt(sc.next());
      
      String kotae = S <= W ? "unsafe" : "safe";
      System.out.println(kotae);
    }  
} Main
import java.util.*;
 
public class Main { //クラス名はMain
    public static void main(String[] args) {
      //整数の入力
      Scanner sc = new Scanner(System.in);
      int S = Integer.parseInt(sc.next());
      int W = Integer.parseInt(sc.next());
      
      String kotae = S <= W ? "unsafe" : "safe";
      System.out.println(kotae);
    }  
}
