import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int s = Integer.parseInt(sc.next());
        int w = Integer.parseInt(sc.next());
        System.out.println(problem164a(s, w));
    }

    private static String problem164a(int s, int w) {
        return (s <= w) ? "unsafe" : "safe";
    }
} import java.util.Scanner; Scanner java.util public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int s = Integer.parseInt(sc.next());
        int w = Integer.parseInt(sc.next());
        System.out.println(problem164a(s, w));
    }

    private static String problem164a(int s, int w) {
        return (s <= w) ? "unsafe" : "safe";
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int s = Integer.parseInt(sc.next());
        int w = Integer.parseInt(sc.next());
        System.out.println(problem164a(s, w));
    } main {
        Scanner sc = new Scanner(System.in);
        int s = Integer.parseInt(sc.next());
        int w = Integer.parseInt(sc.next());
        System.out.println(problem164a(s, w));
    } 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 System.out.println(problem164a(s, w)) System.out.println System.out System System.out problem164a(s, w) problem164a s w String[] args args private static String problem164a(int s, int w) {
        return (s <= w) ? "unsafe" : "safe";
    } problem164a {
        return (s <= w) ? "unsafe" : "safe";
    } return (s <= w) ? "unsafe" : "safe"; (s <= w) ? "unsafe" : "safe" (s <= w) s w "unsafe" "safe" int s s int w w public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int s = Integer.parseInt(sc.next());
        int w = Integer.parseInt(sc.next());
        System.out.println(problem164a(s, w));
    }

    private static String problem164a(int s, int w) {
        return (s <= w) ? "unsafe" : "safe";
    }
} public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int s = Integer.parseInt(sc.next());
        int w = Integer.parseInt(sc.next());
        System.out.println(problem164a(s, w));
    }

    private static String problem164a(int s, int w) {
        return (s <= w) ? "unsafe" : "safe";
    }
} Main
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int s = Integer.parseInt(sc.next());
        int w = Integer.parseInt(sc.next());
        System.out.println(problem164a(s, w));
    }

    private static String problem164a(int s, int w) {
        return (s <= w) ? "unsafe" : "safe";
    }
}