
import java.util.Map.Entry;
import java.util.*;

import org.w3c.dom.css.Counter;

public class Main {
//public class App {

    public static void main(String[] args){
     //スキャン
     Scanner s = new Scanner(System.in);
       // 入力
       int n = Integer.parseInt(s.next());
       int n2 =Integer.parseInt(s.next());
        if(n <= n2){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    }
} import java.util.Map.Entry; Entry java.util.Map import java.util.*; util.* java import org.w3c.dom.css.Counter; Counter org.w3c.dom.css public class Main {
//public class App {

    public static void main(String[] args){
     //スキャン
     Scanner s = new Scanner(System.in);
       // 入力
       int n = Integer.parseInt(s.next());
       int n2 =Integer.parseInt(s.next());
        if(n <= n2){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    }
} Main public static void main(String[] args){
     //スキャン
     Scanner s = new Scanner(System.in);
       // 入力
       int n = Integer.parseInt(s.next());
       int n2 =Integer.parseInt(s.next());
        if(n <= n2){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    } main {
     //スキャン
     Scanner s = new Scanner(System.in);
       // 入力
       int n = Integer.parseInt(s.next());
       int n2 =Integer.parseInt(s.next());
        if(n <= n2){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    } Scanner s = new Scanner(System.in); s new Scanner(System.in) int n = Integer.parseInt(s.next()); n Integer.parseInt(s.next()) Integer.parseInt Integer s.next() s.next s int n2 =Integer.parseInt(s.next()); n2 Integer.parseInt(s.next()) Integer.parseInt Integer s.next() s.next s if(n <= n2){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        } n <= n2 n n2 {
            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 class App {

    public static void main(String[] args){
     //スキャン
     Scanner s = new Scanner(System.in);
       // 入力
       int n = Integer.parseInt(s.next());
       int n2 =Integer.parseInt(s.next());
        if(n <= n2){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    }
} public class Main {
//public class App {

    public static void main(String[] args){
     //スキャン
     Scanner s = new Scanner(System.in);
       // 入力
       int n = Integer.parseInt(s.next());
       int n2 =Integer.parseInt(s.next());
        if(n <= n2){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    }
} Main

import java.util.Map.Entry;
import java.util.*;

import org.w3c.dom.css.Counter;

public class Main {
//public class App {

    public static void main(String[] args){
     //スキャン
     Scanner s = new Scanner(System.in);
       // 入力
       int n = Integer.parseInt(s.next());
       int n2 =Integer.parseInt(s.next());
        if(n <= n2){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    }
}