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

