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