Problem: A TV show called "Guess a number!" is gathering popularity. The whole Berland, the old and the young, are watching the show.

The rules are simple. The host thinks of an integer y and the participants guess it by asking questions to the host. There are four types of acceptable questions:

  * Is it true that y is strictly larger than number x? 
  * Is it true that y is strictly smaller than number x? 
  * Is it true that y is larger than or equal to number x? 
  * Is it true that y is smaller than or equal to number x? 



On each question the host answers truthfully, "yes" or "no".

Given the sequence of questions and answers, find any integer value of y that meets the criteria of all answers. If there isn't such value, print "Impossible".

Input

The first line of the input contains a single integer n (1 ≤ n ≤ 10000) — the number of questions (and answers). Next n lines each contain one question and one answer to it. The format of each line is like that: "sign x answer", where the sign is:

  * ">" (for the first type queries), 
  * "<" (for the second type queries), 
  * ">=" (for the third type queries), 
  * "<=" (for the fourth type queries). 



All values of x are integer and meet the inequation  - 109 ≤ x ≤ 109. The answer is an English letter "Y" (for "yes") or "N" (for "no").

Consequtive elements in lines are separated by a single space.

Output

Print any of such integers y, that the answers to all the queries are correct. The printed number y must meet the inequation  - 2·109 ≤ y ≤ 2·109. If there are many answers, print any of them. If such value doesn't exist, print word "Impossible" (without the quotes).

Examples

Input

4
&gt;= 1 Y
&lt; 3 N
&lt;= -3 N
&gt; 55 N


Output

17


Input

2
&gt; 100 Y
&lt; -100 Y


Output

Impossible

Solution (in JAVA):

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


public class Prob77 {
	
	static BufferedReader br;
	static int start = -2000000000;
	static int end = 2000000000;
	
	public static void main(String[] args) throws NumberFormatException, IOException {
		br = new BufferedReader(new InputStreamReader(System.in));
		int n = Integer.parseInt(br.readLine());
		for (int i = 0; i < n; i++) {
			getCondition (br.readLine().split(" "));
		}
		br.close();
		System.out.println(start);
	}
	private static void getCondition(String[] split) throws IOException {
		int number = Integer.parseInt(split[1]);
		
		switch (split[0]) {
		case ">=":
			if (split[2].equals("Y"))
				moreThanOrEqual(number);
			else
				lessThan(number);
			break;
		case "<":
			if (split[2].equals("Y"))
				lessThan(number);
			else 
				moreThanOrEqual(number);
			break;
	case "<=":
		if (split[2].equals("Y"))
			lessThanOrEqual(number);
		else
			moreThan(number);
		break;
	case ">":
		if (split[2].equals("Y"))
			moreThan(number);
		else
			lessThanOrEqual(number);
		break;

		default:
			break;
		}
		
	}
	

	
	
	private static void end() throws IOException {
		System.out.println("Impossible");
		br.close();
		System.exit(0);
	}
	
	private static void check() throws IOException{
		if (start > end)
			end();
	}
	
	private static void moreThanOrEqual(int number) throws IOException {
		if (number > start){	
			start = number;
			check();
		}
	}
	
	private static void moreThan(int number) throws IOException {
		if (number >= start){	
			start = number + 1;
			check();
		}
		
	}
	
	private static void lessThanOrEqual(int number) throws IOException {
		if (number < end){
			end = number;
			check();
		}
	}
	
	private static void lessThan(int number) throws IOException {
		if (number <= end){
			end = number - 1;
			check();
		}
		
	}


}