import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] tokens = br.readLine().split(" ");
		System.out.println(Integer.parseInt(tokens[0]) > Integer.parseInt(tokens[1]) ? "safe" : "unsafe");
	}
} import java.io.BufferedReader; BufferedReader java.io import java.io.IOException; IOException java.io import java.io.InputStreamReader; InputStreamReader java.io public class Main {
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] tokens = br.readLine().split(" ");
		System.out.println(Integer.parseInt(tokens[0]) > Integer.parseInt(tokens[1]) ? "safe" : "unsafe");
	}
} Main public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] tokens = br.readLine().split(" ");
		System.out.println(Integer.parseInt(tokens[0]) > Integer.parseInt(tokens[1]) ? "safe" : "unsafe");
	} main {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] tokens = br.readLine().split(" ");
		System.out.println(Integer.parseInt(tokens[0]) > Integer.parseInt(tokens[1]) ? "safe" : "unsafe");
	} BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) String[] tokens = br.readLine().split(" "); tokens br.readLine().split(" ") br.readLine().split br.readLine() br.readLine br " " System.out.println(Integer.parseInt(tokens[0]) > Integer.parseInt(tokens[1]) ? "safe" : "unsafe") System.out.println System.out System System.out Integer.parseInt(tokens[0]) > Integer.parseInt(tokens[1]) ? "safe" : "unsafe" Integer.parseInt(tokens[0]) > Integer.parseInt(tokens[1]) Integer.parseInt(tokens[0]) Integer.parseInt Integer tokens[0] tokens 0 Integer.parseInt(tokens[1]) Integer.parseInt Integer tokens[1] tokens 1 "safe" "unsafe" String[] args args public class Main {
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] tokens = br.readLine().split(" ");
		System.out.println(Integer.parseInt(tokens[0]) > Integer.parseInt(tokens[1]) ? "safe" : "unsafe");
	}
} public class Main {
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] tokens = br.readLine().split(" ");
		System.out.println(Integer.parseInt(tokens[0]) > Integer.parseInt(tokens[1]) ? "safe" : "unsafe");
	}
} Main
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] tokens = br.readLine().split(" ");
		System.out.println(Integer.parseInt(tokens[0]) > Integer.parseInt(tokens[1]) ? "safe" : "unsafe");
	}
}
