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.BufferedReader;
import java.io.IOException;


import java.io.PrintWriter;

import java.io.InputStreamReader;
import java.math.BigInteger;
import java.util.*;
public class Main{
static int min,max;
static String op[]={">",">=","<","<="};
public static void  main(String args[]) throws IOException{ 
    Scanner a = new Scanner(new BufferedReader(new InputStreamReader(System.in)));
    int n;
    String s;
    while(a.hasNext()){
    	n=a.nextInt();
    	min=-1999999999;
    	max=1999999999;
    	for(int i=0;i<n;i++){
    		s=a.next();
    		int j;
    		for(j=0;j<4;j++)if(s.equals(op[j]))break;
    		int bound=a.nextInt();
    		s=a.next();
    		if(s.equals("N"))j=3-j;
    		if(j==0&&min<bound+1)min=bound+1;
    		if(j==1&&min<bound)min=bound;
    		if(j==2&&max>bound-1)max=bound-1;
    		if(j==3&&max>bound)max=bound;
    	}
    	//System.out.println(max+" "+min);
    	if(max>=min)System.out.println(min);
    	else System.out.println("Impossible");
    }
  }  
}