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.Arrays;
import java.util.Scanner;

/**
 * Created by lextal on 4/19/14.
 */
public class CodeForces {

    private static final Scanner sc = new Scanner(System.in);
    private static int min = -2000000000;
    private static int max = 2000000000;
    private static boolean verb = true;

    private static void out(String s) {
        if (verb) System.out.println(s);
    }

    private static void leq(int p) {
        out("leq");
        if (max > p) {
            max = p;
        }
    }

    private static void less(int p) {
        out("less");
        if (max >= p) {
            max = p - 1;
        }
    }

    private static void geq(int p) {
        out("geq");
        if (min < p) {
            min = p;
        }
    }

    private static void greater(int p) {
        out("greater");
        if (min <= p) {
            min = p + 1;
        }
    }

    public static void main(String[] args) {
        verb = false;
        int n = Integer.parseInt(sc.nextLine());
        for (int i = 0; i < n; i++) {
            String[] s = sc.nextLine().split(" ");
            int p = Integer.parseInt(s[1]);
            if (s[0].equals(">=")) {
                if (s[2].charAt(0) == 'Y') geq(p); else less(p);
            } else if (s[0].equals("<=")) {
                if (s[2].charAt(0) == 'Y') leq(p); else greater(p);
            } else if (s[0].equals(">")) {
                if (s[2].charAt(0) == 'Y') greater(p); else leq(p);
            } else {
                if (s[2].charAt(0) == 'Y') less(p); else geq(p);
            }
        }
        if (min > max) {
            System.out.println("Impossible");
        } else {
            System.out.println(min);
        }
    }

}