import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner scanner = new Scanner(System.in);
		int s = scanner.nextInt();
		int w = scanner.nextInt();
		
		System.out.println((w>=s)? "unsafe" : "safe");

	} 
} import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {

		Scanner scanner = new Scanner(System.in);
		int s = scanner.nextInt();
		int w = scanner.nextInt();
		
		System.out.println((w>=s)? "unsafe" : "safe");

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

		Scanner scanner = new Scanner(System.in);
		int s = scanner.nextInt();
		int w = scanner.nextInt();
		
		System.out.println((w>=s)? "unsafe" : "safe");

	} main {

		Scanner scanner = new Scanner(System.in);
		int s = scanner.nextInt();
		int w = scanner.nextInt();
		
		System.out.println((w>=s)? "unsafe" : "safe");

	} Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) int s = scanner.nextInt(); s scanner.nextInt() scanner.nextInt scanner int w = scanner.nextInt(); w scanner.nextInt() scanner.nextInt scanner System.out.println((w>=s)? "unsafe" : "safe") System.out.println System.out System System.out (w>=s)? "unsafe" : "safe" (w>=s) w s "unsafe" "safe" String[] args args public class Main {

	public static void main(String[] args) {

		Scanner scanner = new Scanner(System.in);
		int s = scanner.nextInt();
		int w = scanner.nextInt();
		
		System.out.println((w>=s)? "unsafe" : "safe");

	} 
} public class Main {

	public static void main(String[] args) {

		Scanner scanner = new Scanner(System.in);
		int s = scanner.nextInt();
		int w = scanner.nextInt();
		
		System.out.println((w>=s)? "unsafe" : "safe");

	} 
} Main
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner scanner = new Scanner(System.in);
		int s = scanner.nextInt();
		int w = scanner.nextInt();
		
		System.out.println((w>=s)? "unsafe" : "safe");

	} 
}