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