import java.io.*;
import java.math.*;
import java.util.*;
public class Main {

	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		int A = input.nextInt();
		int B = input.nextInt();
		System.out.println(A<=B? "unsafe":"safe");
	}

} import java.io.*; io.* java import java.math.*; math.* java import java.util.*; util.* java public class Main {

	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		int A = input.nextInt();
		int B = input.nextInt();
		System.out.println(A<=B? "unsafe":"safe");
	}

} Main public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		int A = input.nextInt();
		int B = input.nextInt();
		System.out.println(A<=B? "unsafe":"safe");
	} main {
		Scanner input = new Scanner(System.in);
		int A = input.nextInt();
		int B = input.nextInt();
		System.out.println(A<=B? "unsafe":"safe");
	} Scanner input = new Scanner(System.in); input new Scanner(System.in) int A = input.nextInt(); A input.nextInt() input.nextInt input int B = input.nextInt(); B input.nextInt() input.nextInt input System.out.println(A<=B? "unsafe":"safe") System.out.println System.out System System.out A<=B? "unsafe":"safe" A<=B A B "unsafe" "safe" String[] args args public class Main {

	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		int A = input.nextInt();
		int B = input.nextInt();
		System.out.println(A<=B? "unsafe":"safe");
	}

} public class Main {

	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		int A = input.nextInt();
		int B = input.nextInt();
		System.out.println(A<=B? "unsafe":"safe");
	}

} Main
import java.io.*;
import java.math.*;
import java.util.*;
public class Main {

	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		int A = input.nextInt();
		int B = input.nextInt();
		System.out.println(A<=B? "unsafe":"safe");
	}

}