import java.util.*;

public class Main{
	public static void main(String[] args) {
	 Scanner sc = new Scanner(System.in);
     int input1 = sc.nextInt();
     int input2 = sc.nextInt();
     
     if(input1 <= input2) {
      System.out.println("unsafe");
     } else {
      System.out.println("safe");
     }
     
    }
} import java.util.*; util.* java public class Main{
	public static void main(String[] args) {
	 Scanner sc = new Scanner(System.in);
     int input1 = sc.nextInt();
     int input2 = sc.nextInt();
     
     if(input1 <= input2) {
      System.out.println("unsafe");
     } else {
      System.out.println("safe");
     }
     
    }
} Main public static void main(String[] args) {
	 Scanner sc = new Scanner(System.in);
     int input1 = sc.nextInt();
     int input2 = sc.nextInt();
     
     if(input1 <= input2) {
      System.out.println("unsafe");
     } else {
      System.out.println("safe");
     }
     
    } main {
	 Scanner sc = new Scanner(System.in);
     int input1 = sc.nextInt();
     int input2 = sc.nextInt();
     
     if(input1 <= input2) {
      System.out.println("unsafe");
     } else {
      System.out.println("safe");
     }
     
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int input1 = sc.nextInt(); input1 sc.nextInt() sc.nextInt sc int input2 = sc.nextInt(); input2 sc.nextInt() sc.nextInt sc if(input1 <= input2) {
      System.out.println("unsafe");
     } else {
      System.out.println("safe");
     } input1 <= input2 input1 input2 {
      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 sc = new Scanner(System.in);
     int input1 = sc.nextInt();
     int input2 = sc.nextInt();
     
     if(input1 <= input2) {
      System.out.println("unsafe");
     } else {
      System.out.println("safe");
     }
     
    }
} public class Main{
	public static void main(String[] args) {
	 Scanner sc = new Scanner(System.in);
     int input1 = sc.nextInt();
     int input2 = sc.nextInt();
     
     if(input1 <= input2) {
      System.out.println("unsafe");
     } else {
      System.out.println("safe");
     }
     
    }
} Main
import java.util.*;

public class Main{
	public static void main(String[] args) {
	 Scanner sc = new Scanner(System.in);
     int input1 = sc.nextInt();
     int input2 = sc.nextInt();
     
     if(input1 <= input2) {
      System.out.println("unsafe");
     } else {
      System.out.println("safe");
     }
     
    }
}