import java.util.*;
import java.io.*;
public class Main{
  public static void main(String [] args){

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

  }

} import java.util.*; util.* java import java.io.*; io.* java public class Main{
  public static void main(String [] args){

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

  }

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

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

  } main {

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

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

  }

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

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

  }

} Main
import java.util.*;
import java.io.*;
public class Main{
  public static void main(String [] args){

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

  }

}