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.*;

public class guess {
    public static void main(String[] args) throws Exception {
        Scanner in = new Scanner(System.in);
        
        int a = Integer.parseInt(in.nextLine());
        
        long minbound = Integer.MIN_VALUE;
        long maxbound = Integer.MAX_VALUE;
        
        for(int i = 0; i < a; i++) {
            String str = in.nextLine();
            int x = Integer.parseInt(str.substring(str.indexOf(" ") + 1, str.lastIndexOf(" ")));
            String str1 = str.substring(0, 2);
            char c = str.charAt(str.length() - 1);
            if((str1.equals("<=") && c == 'Y') || (str1.equals("> ") && c == 'N')) {
                maxbound = Math.min(maxbound, x);
            }
            if((str1.equals("<=") && c == 'N') || (str1.equals("> ") && c == 'Y')) {
                minbound = Math.max(minbound, x + 1);
            }
            if((str1.equals(">=") && c == 'Y') || (str1.equals("< ") && c == 'N')) {
                minbound = Math.max(minbound, x);
            }
            if((str1.equals(">=") && c == 'N') || (str1.equals("< ") && c == 'Y')) {
                maxbound = Math.min(maxbound, x - 1);
            }
        }
        
        if(maxbound < minbound) System.out.println("Impossible");
        else System.out.println((minbound + maxbound) / 2);
    }
}