import java.util.Scanner;

public class Main {
    Scanner in = new Scanner(System.in);
    public static void main(String[] args) {
        new Main().solve();
    }

    void solve(){
        int w, s;
        s = in.nextInt();
        w = in.nextInt();

        System.out.println( (w >= s) ? "unsafe" : "safe" );

    }

} import java.util.Scanner; Scanner java.util public class Main {
    Scanner in = new Scanner(System.in);
    public static void main(String[] args) {
        new Main().solve();
    }

    void solve(){
        int w, s;
        s = in.nextInt();
        w = in.nextInt();

        System.out.println( (w >= s) ? "unsafe" : "safe" );

    }

} Main Scanner in = new Scanner(System.in); in new Scanner(System.in) public static void main(String[] args) {
        new Main().solve();
    } main {
        new Main().solve();
    } new Main().solve() new Main().solve new Main() String[] args args void solve(){
        int w, s;
        s = in.nextInt();
        w = in.nextInt();

        System.out.println( (w >= s) ? "unsafe" : "safe" );

    } solve {
        int w, s;
        s = in.nextInt();
        w = in.nextInt();

        System.out.println( (w >= s) ? "unsafe" : "safe" );

    } int w w s; s s = in.nextInt() s in.nextInt() in.nextInt in w = in.nextInt() w in.nextInt() in.nextInt in System.out.println( (w >= s) ? "unsafe" : "safe" ) System.out.println System.out System System.out (w >= s) ? "unsafe" : "safe" (w >= s) w s "unsafe" "safe" public class Main {
    Scanner in = new Scanner(System.in);
    public static void main(String[] args) {
        new Main().solve();
    }

    void solve(){
        int w, s;
        s = in.nextInt();
        w = in.nextInt();

        System.out.println( (w >= s) ? "unsafe" : "safe" );

    }

} public class Main {
    Scanner in = new Scanner(System.in);
    public static void main(String[] args) {
        new Main().solve();
    }

    void solve(){
        int w, s;
        s = in.nextInt();
        w = in.nextInt();

        System.out.println( (w >= s) ? "unsafe" : "safe" );

    }

} Main
import java.util.Scanner;

public class Main {
    Scanner in = new Scanner(System.in);
    public static void main(String[] args) {
        new Main().solve();
    }

    void solve(){
        int w, s;
        s = in.nextInt();
        w = in.nextInt();

        System.out.println( (w >= s) ? "unsafe" : "safe" );

    }

}
