import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ

		Scanner scanner = new Scanner(System.in);
		System.out.print(" ");

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

		scanner.close();
     
	}
} import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ

		Scanner scanner = new Scanner(System.in);
		System.out.print(" ");

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

		scanner.close();
     
	}
} Main public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ

		Scanner scanner = new Scanner(System.in);
		System.out.print(" ");

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

		scanner.close();
     
	} main {
		// TODO 自動生成されたメソッド・スタブ

		Scanner scanner = new Scanner(System.in);
		System.out.print(" ");

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

		scanner.close();
     
	} Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) System.out.print(" ") System.out.print System.out System System.out " " int S= scanner.nextInt(); S scanner.nextInt() scanner.nextInt scanner int W = scanner.nextInt(); W scanner.nextInt() scanner.nextInt scanner 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" scanner.close() scanner.close scanner String[] args args public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ

		Scanner scanner = new Scanner(System.in);
		System.out.print(" ");

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

		scanner.close();
     
	}
} public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ

		Scanner scanner = new Scanner(System.in);
		System.out.print(" ");

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

		scanner.close();
     
	}
} Main
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ

		Scanner scanner = new Scanner(System.in);
		System.out.print(" ");

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

		scanner.close();
     
	}
}
