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

public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader bw = new BufferedReader(new InputStreamReader(System.in));
		String s = bw.readLine();
		String[] w = s.split("\\s+");
		int S = Integer.parseInt(w[0]);
		int W = Integer.parseInt(w[1]);
		
		if (W >= S) {
			System.out.println("unsafe");
		}else {
			System.out.println("safe");
		}
		bw.close();
	}
	
	
}	
 import java.io.BufferedReader; BufferedReader java.io import java.io.InputStreamReader; InputStreamReader java.io public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader bw = new BufferedReader(new InputStreamReader(System.in));
		String s = bw.readLine();
		String[] w = s.split("\\s+");
		int S = Integer.parseInt(w[0]);
		int W = Integer.parseInt(w[1]);
		
		if (W >= S) {
			System.out.println("unsafe");
		}else {
			System.out.println("safe");
		}
		bw.close();
	}
	
	
} Main public static void main(String[] args) throws Exception {
		BufferedReader bw = new BufferedReader(new InputStreamReader(System.in));
		String s = bw.readLine();
		String[] w = s.split("\\s+");
		int S = Integer.parseInt(w[0]);
		int W = Integer.parseInt(w[1]);
		
		if (W >= S) {
			System.out.println("unsafe");
		}else {
			System.out.println("safe");
		}
		bw.close();
	} main {
		BufferedReader bw = new BufferedReader(new InputStreamReader(System.in));
		String s = bw.readLine();
		String[] w = s.split("\\s+");
		int S = Integer.parseInt(w[0]);
		int W = Integer.parseInt(w[1]);
		
		if (W >= S) {
			System.out.println("unsafe");
		}else {
			System.out.println("safe");
		}
		bw.close();
	} BufferedReader bw = new BufferedReader(new InputStreamReader(System.in)); bw new BufferedReader(new InputStreamReader(System.in)) String s = bw.readLine(); s bw.readLine() bw.readLine bw String[] w = s.split("\\s+"); w s.split("\\s+") s.split s "\\s+" int S = Integer.parseInt(w[0]); S Integer.parseInt(w[0]) Integer.parseInt Integer w[0] w 0 int W = Integer.parseInt(w[1]); W Integer.parseInt(w[1]) Integer.parseInt Integer w[1] w 1 if (W >= S) {
			System.out.println("unsafe");
		}else {
			System.out.println("safe");
		} W >= S W S {
			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" bw.close() bw.close bw String[] args args public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader bw = new BufferedReader(new InputStreamReader(System.in));
		String s = bw.readLine();
		String[] w = s.split("\\s+");
		int S = Integer.parseInt(w[0]);
		int W = Integer.parseInt(w[1]);
		
		if (W >= S) {
			System.out.println("unsafe");
		}else {
			System.out.println("safe");
		}
		bw.close();
	}
	
	
} public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader bw = new BufferedReader(new InputStreamReader(System.in));
		String s = bw.readLine();
		String[] w = s.split("\\s+");
		int S = Integer.parseInt(w[0]);
		int W = Integer.parseInt(w[1]);
		
		if (W >= S) {
			System.out.println("unsafe");
		}else {
			System.out.println("safe");
		}
		bw.close();
	}
	
	
} Main
import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader bw = new BufferedReader(new InputStreamReader(System.in));
		String s = bw.readLine();
		String[] w = s.split("\\s+");
		int S = Integer.parseInt(w[0]);
		int W = Integer.parseInt(w[1]);
		
		if (W >= S) {
			System.out.println("unsafe");
		}else {
			System.out.println("safe");
		}
		bw.close();
	}
	
	
}	

