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.*;
import java.io.*;
public class Main {
    public static void main(String args[]) throws IOException
    {
        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
        int n=Integer.parseInt(br.readLine());
        long minvalue=-2000000000,maxvalue=2000000000;
        while(n-->0)
        {
            
            String s=br.readLine();
            String s1[]=s.split(" ");
            int x=Integer.parseInt(s1[1]);
            if (s1[0].equals(">"))
            {
                if (s1[2].equals("Y"))
                {
                    if (minvalue<x+1)
                    {
                        minvalue=x+1;
                    }
                }
                else
                {
                    if (maxvalue>x)
                    {
                        maxvalue=x;
                    }
                }
            }
            else if (s1[0].equals(">="))
            {
                if (s1[2].equals("Y"))
                {
                    if (minvalue<x)
                    {
                        minvalue=x;
                    }
                }
                else
                {
                    if (maxvalue>x-1)
                    {
                        maxvalue=x-1;
                    }
                }
            }
            else if (s1[0].equals("<"))
            {
                if (s1[2].equals("Y"))
                {
                    if (maxvalue>x-1)
                    {
                        maxvalue=x-1;
                    }
                }
                else
                {
                    if (minvalue<x)
                    {
                        minvalue=x;
                    }
                }
            }
            else if (s1[0].equals("<="))
            {
                if (s1[2].equals("Y"))
                {
                    if (maxvalue>x)
                    {
                        maxvalue=x;
                    }
                }
                else
                {
                    if (minvalue<x+1)
                    {
                        minvalue=x+1;
                    }
                }
            }
            
        }
        if (minvalue<=maxvalue)
        {
            System.out.println((minvalue+maxvalue)/2);
        }
        else
            System.out.println("Impossible");
    }
}