import java.util.Scanner;
import java.util.Arrays;
import java.util.List;

public class Main {
	public static void main(String[] args) {
	    Scanner sc = new Scanner(System.in);
		String[] array = sc.nextLine().split(" ");
		int sheep = Integer.parseInt(array[0]);
		int wolves = Integer.parseInt(array[1]);
		String result = sheep <= wolves ? "unsafe" : "safe";
	    System.out.println(result);
	}
} import java.util.Scanner; Scanner java.util import java.util.Arrays; Arrays java.util import java.util.List; List java.util public class Main {
	public static void main(String[] args) {
	    Scanner sc = new Scanner(System.in);
		String[] array = sc.nextLine().split(" ");
		int sheep = Integer.parseInt(array[0]);
		int wolves = Integer.parseInt(array[1]);
		String result = sheep <= wolves ? "unsafe" : "safe";
	    System.out.println(result);
	}
} Main public static void main(String[] args) {
	    Scanner sc = new Scanner(System.in);
		String[] array = sc.nextLine().split(" ");
		int sheep = Integer.parseInt(array[0]);
		int wolves = Integer.parseInt(array[1]);
		String result = sheep <= wolves ? "unsafe" : "safe";
	    System.out.println(result);
	} main {
	    Scanner sc = new Scanner(System.in);
		String[] array = sc.nextLine().split(" ");
		int sheep = Integer.parseInt(array[0]);
		int wolves = Integer.parseInt(array[1]);
		String result = sheep <= wolves ? "unsafe" : "safe";
	    System.out.println(result);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String[] array = sc.nextLine().split(" "); array sc.nextLine().split(" ") sc.nextLine().split sc.nextLine() sc.nextLine sc " " int sheep = Integer.parseInt(array[0]); sheep Integer.parseInt(array[0]) Integer.parseInt Integer array[0] array 0 int wolves = Integer.parseInt(array[1]); wolves Integer.parseInt(array[1]) Integer.parseInt Integer array[1] array 1 String result = sheep <= wolves ? "unsafe" : "safe"; result sheep <= wolves ? "unsafe" : "safe" sheep <= wolves sheep wolves "unsafe" "safe" System.out.println(result) System.out.println System.out System System.out result String[] args args public class Main {
	public static void main(String[] args) {
	    Scanner sc = new Scanner(System.in);
		String[] array = sc.nextLine().split(" ");
		int sheep = Integer.parseInt(array[0]);
		int wolves = Integer.parseInt(array[1]);
		String result = sheep <= wolves ? "unsafe" : "safe";
	    System.out.println(result);
	}
} public class Main {
	public static void main(String[] args) {
	    Scanner sc = new Scanner(System.in);
		String[] array = sc.nextLine().split(" ");
		int sheep = Integer.parseInt(array[0]);
		int wolves = Integer.parseInt(array[1]);
		String result = sheep <= wolves ? "unsafe" : "safe";
	    System.out.println(result);
	}
} Main
import java.util.Scanner;
import java.util.Arrays;
import java.util.List;

public class Main {
	public static void main(String[] args) {
	    Scanner sc = new Scanner(System.in);
		String[] array = sc.nextLine().split(" ");
		int sheep = Integer.parseInt(array[0]);
		int wolves = Integer.parseInt(array[1]);
		String result = sheep <= wolves ? "unsafe" : "safe";
	    System.out.println(result);
	}
}
