import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        Integer S = input.nextInt();
        Integer W = input.nextInt();

        if (S <= W) 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 input = new Scanner(System.in);
        Integer S = input.nextInt();
        Integer W = input.nextInt();

        if (S <= W) System.out.println("unsafe");
        else System.out.println("safe");
    }
} Main public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        Integer S = input.nextInt();
        Integer W = input.nextInt();

        if (S <= W) System.out.println("unsafe");
        else System.out.println("safe");
    } main {
        Scanner input = new Scanner(System.in);
        Integer S = input.nextInt();
        Integer W = input.nextInt();

        if (S <= W) System.out.println("unsafe");
        else System.out.println("safe");
    } Scanner input = new Scanner(System.in); input new Scanner(System.in) Integer S = input.nextInt(); S input.nextInt() input.nextInt input Integer W = input.nextInt(); W input.nextInt() input.nextInt input if (S <= W) System.out.println("unsafe");
        else System.out.println("safe"); S <= W S W System.out.println("unsafe") System.out.println System.out System System.out "unsafe" 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 input = new Scanner(System.in);
        Integer S = input.nextInt();
        Integer W = input.nextInt();

        if (S <= W) System.out.println("unsafe");
        else System.out.println("safe");
    }
} public class Main {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        Integer S = input.nextInt();
        Integer W = input.nextInt();

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

public class Main {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        Integer S = input.nextInt();
        Integer W = input.nextInt();

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