
import java.io.IOException;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) throws IOException {
		Scanner sc = new Scanner(System.in);
		
		int n  = sc.nextInt();

		int m  = sc.nextInt();
		
		System.out.println( n>m ? "safe" : "unsafe");
	}
	
	
} import java.io.IOException; IOException java.io import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) throws IOException {
		Scanner sc = new Scanner(System.in);
		
		int n  = sc.nextInt();

		int m  = sc.nextInt();
		
		System.out.println( n>m ? "safe" : "unsafe");
	}
	
	
} Main public static void main(String[] args) throws IOException {
		Scanner sc = new Scanner(System.in);
		
		int n  = sc.nextInt();

		int m  = sc.nextInt();
		
		System.out.println( n>m ? "safe" : "unsafe");
	} main {
		Scanner sc = new Scanner(System.in);
		
		int n  = sc.nextInt();

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

	public static void main(String[] args) throws IOException {
		Scanner sc = new Scanner(System.in);
		
		int n  = sc.nextInt();

		int m  = sc.nextInt();
		
		System.out.println( n>m ? "safe" : "unsafe");
	}
	
	
} public class Main {

	public static void main(String[] args) throws IOException {
		Scanner sc = new Scanner(System.in);
		
		int n  = sc.nextInt();

		int m  = sc.nextInt();
		
		System.out.println( n>m ? "safe" : "unsafe");
	}
	
	
} Main

import java.io.IOException;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) throws IOException {
		Scanner sc = new Scanner(System.in);
		
		int n  = sc.nextInt();

		int m  = sc.nextInt();
		
		System.out.println( n>m ? "safe" : "unsafe");
	}
	
	
}
