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.IOException;
import java.util.HashMap;
import java.util.Scanner;

public class B {
    public static void main(String[] args) throws IOException {
        Scanner s = new Scanner(System.in);

        int n = Integer.parseInt(s.next());
        int LimitRight = 2000000000;
        int LimitLeft = -2000000000;
        boolean flg = true;

        for (int i = 0; i < n; i++) {
            String operation = s.next();
            int number = Integer.parseInt(s.next());
            String can = s.next();

            if (operation.equals(">")) {
                if (can.equals("Y")) {
                    if (LimitRight <= number) {
                        flg = false;
                        break;
                    }
                    LimitLeft = Math.max(number + 1, LimitLeft);
                } else {
                    if (LimitLeft > number) {
                        flg = false;
                        break;
                    }
                    LimitRight = Math.min(LimitRight, number);
                }
            } else if (operation.equals(">=")) {
                if (can.equals("Y")) {
                    if (LimitRight < number) {
                        flg = false;
                        break;
                    }
                    LimitLeft = Math.max(number, LimitLeft);
                } else {
                    if (LimitLeft >= number) {
                        flg = false;
                        break;
                    }

                    LimitRight = Math.min(number - 1, LimitRight);
                }
            } else if (operation.equals("<")) {
                if (can.equals("Y")) {
                    if (LimitLeft >= number) {
                        flg = false;
                        break;
                    }
                    LimitRight = Math.min(number - 1, LimitRight);
                } else {
                    if (LimitRight < number) {
                        flg = false;
                        break;
                    }
                    LimitLeft = Math.max(LimitLeft, number);
                }
            } else if (operation.equals("<=")) {
                if (can.equals("Y")) {
                    if (LimitLeft > number) {
                        flg = false;
                        break;
                    }
                    LimitRight = Math.min(LimitRight, number);
                } else {
                    if (LimitRight <= number) {
                        flg = false;
                        break;
                    }

                    LimitLeft = Math.max(number + 1, LimitLeft);
                }
            }
        }
        if (LimitRight >= LimitLeft && flg) {
            System.out.println(LimitLeft);
        } else {
            System.out.println("Impossible");
        }
    }
}