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.BufferedInputStream;
import java.util.Scanner;

/**
 * Created by jizhe on 2015/12/18.
 */
public class GuessANumber {
    public static void main(String[] args) {
        Scanner in = new Scanner(new BufferedInputStream(System.in));

        int N = in.nextInt();

        int left = Integer.MIN_VALUE/2, right = Integer.MAX_VALUE/2;
        //System.out.printf("left: %d, right: %d\n", left, right);
        boolean ls = false, rs = false;
        for( int i = 0; i < N; i++ )
        {
            String s1 = in.next();
            int number = Integer.parseInt(in.next());
            String s2 = in.next();
            //System.out.printf("s1: %s, number: %d, s2: %s\n", s1, number, s2);
            if( s1.equals(">=") )
            {
                if( s2.equals("Y") )
                {
                    ls = left >= number ? ls : false;
                    left = Math.max(left, number);
                }
                else
                {
                    rs = right < number ? rs : true;
                    right = Math.min(right, number);
                }
            }
            else if( s1.equals("<=") )
            {
                if( s2.equals("Y") )
                {
                    rs = right <= number ? rs : false;
                    right = Math.min(right, number);

                }
                else
                {
                    ls = left > number ? ls : true;
                    left = Math.max(left, number);

                }
            }
            else if( s1.equals(">") )
            {
                if( s2.equals("Y") )
                {
                    ls = left > number ? ls : true;
                    left = Math.max(left, number);
                }
                else
                {
                    rs = right <= number ? rs : false;
                    right = Math.min(right, number);
                }
            }
            else//<
            {
                if( s2.equals("Y") )
                {
                    rs = right < number ? rs : true;
                    right = Math.min(right, number);
                }
                else
                {
                    ls = left >= number ? ls : false;
                    left = Math.max(left, number);
                }
            }
            //System.out.printf("left: %d, right: %d, ls: %b, rs: %b\n", left, right, ls, rs);
        }
        if (left > right || (left == right - 1 && ls && rs) || ((left == right) && (ls || rs))) {
            System.out.printf("Impossible\n");
            return;
        }
        if( !ls )
        {
            System.out.printf("%d\n", left);
        }
        else
        {
            System.out.printf("%d\n", left+1);
        }
    }
}