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