import java.util.*;
 
public class Main {
	public static void main (String[] args) {
		Scanner in = new Scanner(System.in);
		
		int A = in.nextInt();
		int B = in.nextInt();
		
		if(A > B){
		    System.out.println("safe");
		}else{
		    System.out.println("unsafe");
		}

	}
} import java.util.*; util.* java public class Main {
	public static void main (String[] args) {
		Scanner in = new Scanner(System.in);
		
		int A = in.nextInt();
		int B = in.nextInt();
		
		if(A > B){
		    System.out.println("safe");
		}else{
		    System.out.println("unsafe");
		}

	}
} Main public static void main (String[] args) {
		Scanner in = new Scanner(System.in);
		
		int A = in.nextInt();
		int B = in.nextInt();
		
		if(A > B){
		    System.out.println("safe");
		}else{
		    System.out.println("unsafe");
		}

	} main {
		Scanner in = new Scanner(System.in);
		
		int A = in.nextInt();
		int B = in.nextInt();
		
		if(A > B){
		    System.out.println("safe");
		}else{
		    System.out.println("unsafe");
		}

	} Scanner in = new Scanner(System.in); in new Scanner(System.in) int A = in.nextInt(); A in.nextInt() in.nextInt in int B = in.nextInt(); B in.nextInt() in.nextInt in if(A > B){
		    System.out.println("safe");
		}else{
		    System.out.println("unsafe");
		} A > B A B {
		    System.out.println("safe");
		} System.out.println("safe") System.out.println System.out System System.out "safe" {
		    System.out.println("unsafe");
		} System.out.println("unsafe") System.out.println System.out System System.out "unsafe" String[] args args public class Main {
	public static void main (String[] args) {
		Scanner in = new Scanner(System.in);
		
		int A = in.nextInt();
		int B = in.nextInt();
		
		if(A > B){
		    System.out.println("safe");
		}else{
		    System.out.println("unsafe");
		}

	}
} public class Main {
	public static void main (String[] args) {
		Scanner in = new Scanner(System.in);
		
		int A = in.nextInt();
		int B = in.nextInt();
		
		if(A > B){
		    System.out.println("safe");
		}else{
		    System.out.println("unsafe");
		}

	}
} Main
import java.util.*;
 
public class Main {
	public static void main (String[] args) {
		Scanner in = new Scanner(System.in);
		
		int A = in.nextInt();
		int B = in.nextInt();
		
		if(A > B){
		    System.out.println("safe");
		}else{
		    System.out.println("unsafe");
		}

	}
}