import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner scanner = new Scanner(System.in);
		String[] list = scanner.nextLine().split(" ");

		if(Integer.parseInt(list[0]) <= Integer.parseInt(list[1])) {
			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);
		String[] list = scanner.nextLine().split(" ");

		if(Integer.parseInt(list[0]) <= Integer.parseInt(list[1])) {
			System.out.println("unsafe");
		}else {
			System.out.println("safe");
		}

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

		Scanner scanner = new Scanner(System.in);
		String[] list = scanner.nextLine().split(" ");

		if(Integer.parseInt(list[0]) <= Integer.parseInt(list[1])) {
			System.out.println("unsafe");
		}else {
			System.out.println("safe");
		}

	} main {

		Scanner scanner = new Scanner(System.in);
		String[] list = scanner.nextLine().split(" ");

		if(Integer.parseInt(list[0]) <= Integer.parseInt(list[1])) {
			System.out.println("unsafe");
		}else {
			System.out.println("safe");
		}

	} Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) String[] list = scanner.nextLine().split(" "); list scanner.nextLine().split(" ") scanner.nextLine().split scanner.nextLine() scanner.nextLine scanner " " if(Integer.parseInt(list[0]) <= Integer.parseInt(list[1])) {
			System.out.println("unsafe");
		}else {
			System.out.println("safe");
		} Integer.parseInt(list[0]) <= Integer.parseInt(list[1]) Integer.parseInt(list[0]) Integer.parseInt Integer list[0] list 0 Integer.parseInt(list[1]) Integer.parseInt Integer list[1] list 1 {
			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);
		String[] list = scanner.nextLine().split(" ");

		if(Integer.parseInt(list[0]) <= Integer.parseInt(list[1])) {
			System.out.println("unsafe");
		}else {
			System.out.println("safe");
		}

	}
} public class Main {

	public static void main(String[] args) {

		Scanner scanner = new Scanner(System.in);
		String[] list = scanner.nextLine().split(" ");

		if(Integer.parseInt(list[0]) <= Integer.parseInt(list[1])) {
			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);
		String[] list = scanner.nextLine().split(" ");

		if(Integer.parseInt(list[0]) <= Integer.parseInt(list[1])) {
			System.out.println("unsafe");
		}else {
			System.out.println("safe");
		}

	}
}