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 static java.lang.Math.max;
import static java.lang.Math.min;

import java.util.Scanner;


public class GuessNumber {
    private int lb = -2000000000;
    private int ub = 2000000000;

    public static void main(final String... args) {
        GuessNumber game = new GuessNumber();
        game.run();
    }

    private void run() {
        Scanner in = new Scanner(System.in);

        int qa = in.nextInt();

        for (int i = 0; i < qa; i++) {
            Guess guess = new Guess();
            guess.condition = in.next();
            guess.value = in.nextInt();
            guess.yes = in.next().equals("Y");

            updateBounds(guess);
        }

        if (lb <= ub) {
            System.out.println(lb);
        } else {
            System.out.println("Impossible");
        }
    }

    private void updateBounds(final Guess guess) {
        if ((guess.condition.equals(">=") && guess.yes) ||
                (guess.condition.equals("<") && !guess.yes)) {
            lb = max(guess.value, lb);
        }

        if ((guess.condition.equals("<=") && guess.yes) ||
                (guess.condition.equals(">") && !guess.yes)) {
            ub = min(guess.value, ub);
        }

        if ((guess.condition.equals(">") && guess.yes) ||
                (guess.condition.equals("<=") && !guess.yes)) {
            lb = max(lb, guess.value + 1);
        }

        if ((guess.condition.equals("<") && guess.yes) ||
                (guess.condition.equals(">=") && !guess.yes)) {
            ub = min(ub, guess.value - 1);
        }
    }

    private class Guess {
        String condition;

        int value;

        boolean yes;
    }
}