import java.util.Scanner;
public class Main {
	  public static void main(String args[]){
	 Scanner scanner = new Scanner(System.in);

int a=scanner.nextInt();
int b=scanner.nextInt();
int c=a-b;
	if(c>0) {
		System.out.println("safe");
	}
	else{
		System.out.println("unsafe");
	}
}
	  } import java.util.Scanner; Scanner java.util public class Main {
	  public static void main(String args[]){
	 Scanner scanner = new Scanner(System.in);

int a=scanner.nextInt();
int b=scanner.nextInt();
int c=a-b;
	if(c>0) {
		System.out.println("safe");
	}
	else{
		System.out.println("unsafe");
	}
}
	  } Main public static void main(String args[]){
	 Scanner scanner = new Scanner(System.in);

int a=scanner.nextInt();
int b=scanner.nextInt();
int c=a-b;
	if(c>0) {
		System.out.println("safe");
	}
	else{
		System.out.println("unsafe");
	}
} main {
	 Scanner scanner = new Scanner(System.in);

int a=scanner.nextInt();
int b=scanner.nextInt();
int c=a-b;
	if(c>0) {
		System.out.println("safe");
	}
	else{
		System.out.println("unsafe");
	}
} Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) int a=scanner.nextInt(); a scanner.nextInt() scanner.nextInt scanner int b=scanner.nextInt(); b scanner.nextInt() scanner.nextInt scanner int c=a-b; c a-b a b if(c>0) {
		System.out.println("safe");
	}
	else{
		System.out.println("unsafe");
	} c>0 c 0 {
		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 scanner = new Scanner(System.in);

int a=scanner.nextInt();
int b=scanner.nextInt();
int c=a-b;
	if(c>0) {
		System.out.println("safe");
	}
	else{
		System.out.println("unsafe");
	}
}
	  } public class Main {
	  public static void main(String args[]){
	 Scanner scanner = new Scanner(System.in);

int a=scanner.nextInt();
int b=scanner.nextInt();
int c=a-b;
	if(c>0) {
		System.out.println("safe");
	}
	else{
		System.out.println("unsafe");
	}
}
	  } Main
import java.util.Scanner;
public class Main {
	  public static void main(String args[]){
	 Scanner scanner = new Scanner(System.in);

int a=scanner.nextInt();
int b=scanner.nextInt();
int c=a-b;
	if(c>0) {
		System.out.println("safe");
	}
	else{
		System.out.println("unsafe");
	}
}
	  }