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.util.Scanner;


public class GuessANumber {

	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		int n = in.nextInt();
		in.nextLine();
		int min = -2000000000, max = 2000000000;
		String[] line;
		for(int i = 0; i < n; i++){
			line = in.nextLine().split(" ");
			int num = Integer.parseInt(line[1]);
			if(line[2].equals("N")){
				transform(line);
			}
			if(line[0].equals(">=")){
				if(min < num){
					min = num;
				}
			} else if(line[0].equals("<=")){
				if(max > num){
					max = num;
				}
			} else if(line[0].equals(">")){
				if(min <= num){
					min = num + 1;
				}
			} else{
				if(max >= num){
					max = num - 1;
				}
			}
		}
		if(min <= max){
			System.out.println(min);
		}else{
			System.out.println("Impossible");
		}
	}

	private static void transform(String[] line) {
		if(line[0].equals(">=")){
			line[0] = "<";
		} else if(line[0].equals("<=")){
			line[0] = ">";
		} else if(line[0].equals(">")){
			line[0] = "<=";
		} else{
			line[0] = ">=";
		}
	}

}