import java.util.Scanner;

public class Main {
    
    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);

        int sheep = scanner.nextInt();
        int wolves = scanner.nextInt();

        if(sheep <= wolves) {
            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 scanner = new Scanner(System.in);

        int sheep = scanner.nextInt();
        int wolves = scanner.nextInt();

        if(sheep <= wolves) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }

    }
} Main public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);

        int sheep = scanner.nextInt();
        int wolves = scanner.nextInt();

        if(sheep <= wolves) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }

    } main {

        Scanner scanner = new Scanner(System.in);

        int sheep = scanner.nextInt();
        int wolves = scanner.nextInt();

        if(sheep <= wolves) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }

    } Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) int sheep = scanner.nextInt(); sheep scanner.nextInt() scanner.nextInt scanner int wolves = scanner.nextInt(); wolves scanner.nextInt() scanner.nextInt scanner if(sheep <= wolves) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        } sheep <= wolves sheep wolves {
            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 scanner = new Scanner(System.in);

        int sheep = scanner.nextInt();
        int wolves = scanner.nextInt();

        if(sheep <= wolves) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }

    }
} public class Main {
    
    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);

        int sheep = scanner.nextInt();
        int wolves = scanner.nextInt();

        if(sheep <= wolves) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }

    }
} Main
import java.util.Scanner;

public class Main {
    
    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);

        int sheep = scanner.nextInt();
        int wolves = scanner.nextInt();

        if(sheep <= wolves) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }

    }
}