import java.io.File;
import java.util.Scanner;

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

	}
} import java.io.File; File java.io import java.util.Scanner; Scanner 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();
		System.out.println(w<s?"safe":"unsafe");

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

	} main {
		Scanner sc = new Scanner(System.in);
		int s = sc.nextInt(); int w = sc.nextInt();
		System.out.println(w<s?"safe":"unsafe");

	} 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 System.out.println(w<s?"safe":"unsafe") System.out.println System.out System System.out w<s?"safe":"unsafe" w<s w s "safe" "unsafe" 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();
		System.out.println(w<s?"safe":"unsafe");

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

	}
} Main
import java.io.File;
import java.util.Scanner;

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

	}
}
