import java.util.*;

public class Main {

    Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        new Main().run();
    }

    void run() {

        int n = sc.nextInt();
        int m = sc.nextInt();

        if (n <= m) {
            System.out.println("unsafe\n");
        } else {
            System.out.println("safe\n");
        }
    }
} import java.util.*; util.* java public class Main {

    Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        new Main().run();
    }

    void run() {

        int n = sc.nextInt();
        int m = sc.nextInt();

        if (n <= m) {
            System.out.println("unsafe\n");
        } else {
            System.out.println("safe\n");
        }
    }
} Main Scanner sc = new Scanner(System.in); sc new Scanner(System.in) public static void main(String[] args) {
        new Main().run();
    } main {
        new Main().run();
    } new Main().run() new Main().run new Main() String[] args args void run() {

        int n = sc.nextInt();
        int m = sc.nextInt();

        if (n <= m) {
            System.out.println("unsafe\n");
        } else {
            System.out.println("safe\n");
        }
    } run {

        int n = sc.nextInt();
        int m = sc.nextInt();

        if (n <= m) {
            System.out.println("unsafe\n");
        } else {
            System.out.println("safe\n");
        }
    } int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc int m = sc.nextInt(); m sc.nextInt() sc.nextInt sc if (n <= m) {
            System.out.println("unsafe\n");
        } else {
            System.out.println("safe\n");
        } n <= m n m {
            System.out.println("unsafe\n");
        } System.out.println("unsafe\n") System.out.println System.out System System.out "unsafe\n" {
            System.out.println("safe\n");
        } System.out.println("safe\n") System.out.println System.out System System.out "safe\n" public class Main {

    Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        new Main().run();
    }

    void run() {

        int n = sc.nextInt();
        int m = sc.nextInt();

        if (n <= m) {
            System.out.println("unsafe\n");
        } else {
            System.out.println("safe\n");
        }
    }
} public class Main {

    Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        new Main().run();
    }

    void run() {

        int n = sc.nextInt();
        int m = sc.nextInt();

        if (n <= m) {
            System.out.println("unsafe\n");
        } else {
            System.out.println("safe\n");
        }
    }
} Main
import java.util.*;

public class Main {

    Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        new Main().run();
    }

    void run() {

        int n = sc.nextInt();
        int m = sc.nextInt();

        if (n <= m) {
            System.out.println("unsafe\n");
        } else {
            System.out.println("safe\n");
        }
    }
}
