import java.util.*;

public class Main {

    public static void main(String args[]) {

        // 入力
        Scanner sc = new Scanner(System.in);
        int s = Integer.parseInt(sc.next());
        int w = Integer.parseInt(sc.next());
        sc.close();

        // 主処理
        boolean judge = s <= w;
        String result = judge ? "unsafe" : "safe";

        // 出力
        System.out.println(result);
    }
} import java.util.*; util.* java public class Main {

    public static void main(String args[]) {

        // 入力
        Scanner sc = new Scanner(System.in);
        int s = Integer.parseInt(sc.next());
        int w = Integer.parseInt(sc.next());
        sc.close();

        // 主処理
        boolean judge = s <= w;
        String result = judge ? "unsafe" : "safe";

        // 出力
        System.out.println(result);
    }
} Main public static void main(String args[]) {

        // 入力
        Scanner sc = new Scanner(System.in);
        int s = Integer.parseInt(sc.next());
        int w = Integer.parseInt(sc.next());
        sc.close();

        // 主処理
        boolean judge = s <= w;
        String result = judge ? "unsafe" : "safe";

        // 出力
        System.out.println(result);
    } main {

        // 入力
        Scanner sc = new Scanner(System.in);
        int s = Integer.parseInt(sc.next());
        int w = Integer.parseInt(sc.next());
        sc.close();

        // 主処理
        boolean judge = s <= w;
        String result = judge ? "unsafe" : "safe";

        // 出力
        System.out.println(result);
    } 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 sc.close() sc.close sc boolean judge = s <= w; judge s <= w s w String result = judge ? "unsafe" : "safe"; result judge ? "unsafe" : "safe" judge "unsafe" "safe" System.out.println(result) System.out.println System.out System System.out result String args[] args public class Main {

    public static void main(String args[]) {

        // 入力
        Scanner sc = new Scanner(System.in);
        int s = Integer.parseInt(sc.next());
        int w = Integer.parseInt(sc.next());
        sc.close();

        // 主処理
        boolean judge = s <= w;
        String result = judge ? "unsafe" : "safe";

        // 出力
        System.out.println(result);
    }
} public class Main {

    public static void main(String args[]) {

        // 入力
        Scanner sc = new Scanner(System.in);
        int s = Integer.parseInt(sc.next());
        int w = Integer.parseInt(sc.next());
        sc.close();

        // 主処理
        boolean judge = s <= w;
        String result = judge ? "unsafe" : "safe";

        // 出力
        System.out.println(result);
    }
} Main
import java.util.*;

public class Main {

    public static void main(String args[]) {

        // 入力
        Scanner sc = new Scanner(System.in);
        int s = Integer.parseInt(sc.next());
        int w = Integer.parseInt(sc.next());
        sc.close();

        // 主処理
        boolean judge = s <= w;
        String result = judge ? "unsafe" : "safe";

        // 出力
        System.out.println(result);
    }
}
