import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        String[] in = s.nextLine().split(" ");
        int S = Integer.parseInt(in[0]);
        int W = Integer.parseInt(in[1]);

        if (W >= S) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }
    }
} import java.util.Scanner; Scanner java.util public class Main {

    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        String[] in = s.nextLine().split(" ");
        int S = Integer.parseInt(in[0]);
        int W = Integer.parseInt(in[1]);

        if (W >= S) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }
    }
} Main public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        String[] in = s.nextLine().split(" ");
        int S = Integer.parseInt(in[0]);
        int W = Integer.parseInt(in[1]);

        if (W >= S) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }
    } main {
        Scanner s = new Scanner(System.in);
        String[] in = s.nextLine().split(" ");
        int S = Integer.parseInt(in[0]);
        int W = Integer.parseInt(in[1]);

        if (W >= S) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }
    } Scanner s = new Scanner(System.in); s new Scanner(System.in) String[] in = s.nextLine().split(" "); in s.nextLine().split(" ") s.nextLine().split s.nextLine() s.nextLine s " " int S = Integer.parseInt(in[0]); S Integer.parseInt(in[0]) Integer.parseInt Integer in[0] in 0 int W = Integer.parseInt(in[1]); W Integer.parseInt(in[1]) Integer.parseInt Integer in[1] in 1 if (W >= S) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        } W >= S W S {
            System.out.println("unsafe");
        } System.out.println("unsafe") System.out.println System.out System System.out "unsafe" {
            System.out.println("safe");
        } System.out.println("safe") System.out.println System.out System System.out "safe" String[] args args public class Main {

    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        String[] in = s.nextLine().split(" ");
        int S = Integer.parseInt(in[0]);
        int W = Integer.parseInt(in[1]);

        if (W >= S) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }
    }
} public class Main {

    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        String[] in = s.nextLine().split(" ");
        int S = Integer.parseInt(in[0]);
        int W = Integer.parseInt(in[1]);

        if (W >= S) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }
    }
} Main
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        String[] in = s.nextLine().split(" ");
        int S = Integer.parseInt(in[0]);
        int W = Integer.parseInt(in[1]);

        if (W >= S) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }
    }
}