import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int s = sc.nextInt();
    int w = sc.nextInt();
    String msg = (s>w) ? "safe" : "unsafe";
    System.out.println(msg);
  }
} import java.util.*; util.* java public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int s = sc.nextInt();
    int w = sc.nextInt();
    String msg = (s>w) ? "safe" : "unsafe";
    System.out.println(msg);
  }
} Main public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int s = sc.nextInt();
    int w = sc.nextInt();
    String msg = (s>w) ? "safe" : "unsafe";
    System.out.println(msg);
  } main {
    Scanner sc = new Scanner(System.in);
    int s = sc.nextInt();
    int w = sc.nextInt();
    String msg = (s>w) ? "safe" : "unsafe";
    System.out.println(msg);
  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int s = sc.nextInt(); s sc.nextInt() sc.nextInt sc int w = sc.nextInt(); w sc.nextInt() sc.nextInt sc String msg = (s>w) ? "safe" : "unsafe"; msg (s>w) ? "safe" : "unsafe" (s>w) s w "safe" "unsafe" System.out.println(msg) System.out.println System.out System System.out msg String[] args args public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int s = sc.nextInt();
    int w = sc.nextInt();
    String msg = (s>w) ? "safe" : "unsafe";
    System.out.println(msg);
  }
} public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int s = sc.nextInt();
    int w = sc.nextInt();
    String msg = (s>w) ? "safe" : "unsafe";
    System.out.println(msg);
  }
} Main
import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int s = sc.nextInt();
    int w = sc.nextInt();
    String msg = (s>w) ? "safe" : "unsafe";
    System.out.println(msg);
  }
}