import java.io.*;
import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        PrintWriter out = new PrintWriter(System.out);
        
        final int S = Integer.parseInt(sc.next());
        final int W = Integer.parseInt(sc.next());
        




        
        out.println(S <= W ? "unsafe" : "safe");
        
        out.flush();
    }
} import java.io.*; io.* java import java.util.*; util.* java public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        PrintWriter out = new PrintWriter(System.out);
        
        final int S = Integer.parseInt(sc.next());
        final int W = Integer.parseInt(sc.next());
        




        
        out.println(S <= W ? "unsafe" : "safe");
        
        out.flush();
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        PrintWriter out = new PrintWriter(System.out);
        
        final int S = Integer.parseInt(sc.next());
        final int W = Integer.parseInt(sc.next());
        




        
        out.println(S <= W ? "unsafe" : "safe");
        
        out.flush();
    } main {
        Scanner sc = new Scanner(System.in);
        PrintWriter out = new PrintWriter(System.out);
        
        final int S = Integer.parseInt(sc.next());
        final int W = Integer.parseInt(sc.next());
        




        
        out.println(S <= W ? "unsafe" : "safe");
        
        out.flush();
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) PrintWriter out = new PrintWriter(System.out); out new PrintWriter(System.out) final int S = Integer.parseInt(sc.next()); S Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc final int W = Integer.parseInt(sc.next()); W Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc out.println(S <= W ? "unsafe" : "safe") out.println out S <= W ? "unsafe" : "safe" S <= W S W "unsafe" "safe" out.flush() out.flush out String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        PrintWriter out = new PrintWriter(System.out);
        
        final int S = Integer.parseInt(sc.next());
        final int W = Integer.parseInt(sc.next());
        




        
        out.println(S <= W ? "unsafe" : "safe");
        
        out.flush();
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        PrintWriter out = new PrintWriter(System.out);
        
        final int S = Integer.parseInt(sc.next());
        final int W = Integer.parseInt(sc.next());
        




        
        out.println(S <= W ? "unsafe" : "safe");
        
        out.flush();
    }
} Main
import java.io.*;
import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        PrintWriter out = new PrintWriter(System.out);
        
        final int S = Integer.parseInt(sc.next());
        final int W = Integer.parseInt(sc.next());
        




        
        out.println(S <= W ? "unsafe" : "safe");
        
        out.flush();
    }
}