import java.util.*;

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

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