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.InputStreamReader;
import java.util.Scanner;
import java.util.StringTokenizer;

public class Main {

    /**
     * @param args
     */
    public static void main(String[] args) {

        Scanner scanner = new Scanner(new InputStreamReader(System.in));

        int larger = -2000000000;
        int smaller = 2000000000;

        int n = scanner.nextInt();
        scanner.nextLine();

        for (int i = 0; i < n; i++) {
            StringTokenizer tk = new StringTokenizer(scanner.nextLine());

            String operation = tk.nextToken();
            int number = Integer.parseInt(tk.nextToken());
            String YorN = tk.nextToken();

            if (operation.equalsIgnoreCase(">="))
                if (YorN.equalsIgnoreCase("Y")) {
                    if (number - 1 > larger)
                        larger = number - 1;
                } else {
                    if (number < smaller)
                        smaller = number;
                }

            if (operation.equalsIgnoreCase(">"))
                if (YorN.equalsIgnoreCase("Y")) {
                    if (number > larger)
                        larger = number;
                } else {
                    if (number + 1 < smaller)
                        smaller = number + 1;
                }

            if (operation.equalsIgnoreCase("<="))
                if (YorN.equalsIgnoreCase("Y")) {
                    if (number + 1 < smaller)
                        smaller = number + 1;
                } else {
                    if (number > larger)
                        larger = number;
                }

            if (operation.equalsIgnoreCase("<"))
                if (YorN.equalsIgnoreCase("Y")) {
                    if (number < smaller)
                        smaller = number;
                } else {
                    if (number - 1 > larger)
                        larger = number - 1;
                }
        }

        if (smaller - 1 <= larger)
            System.out.println("Impossible");
        else
            System.out.println(larger + 1);


    }

}