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.*;
import java.util.*;
public class Guess {
	public static void main(String[] args) throws IOException{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int N = Integer.parseInt(br.readLine());
		boolean fmin = false;
		boolean fmax = false;
		int min = 0, max = 0;
		for(int i = 0; i < N; i++) {
			StringTokenizer st = new StringTokenizer(br.readLine());
			String s1 = st.nextToken();
			int n = Integer.parseInt(st.nextToken());
			boolean f = st.nextToken().equals("Y");
			if(s1.equals("<")) {
				if(!f) {
					if(!fmin) {min = n; fmin=true;} 
					min = Math.max(min,n); 
				}
				else {
					if(!fmax) {max = n-1; fmax=true;}
					max = Math.min(max,n-1); 
				}
			}
			else if(s1.equals("<=")) {
				if(!f) {
					if(!fmin) {min = n+1;fmin = true;}
					min = Math.max(min,n+1); 

				}
				else {
					if(!fmax) {max = n; fmax = true;}
					max = Math.min(max,n); 
				}
			}
			else if(s1.equals(">")) {
				if(f) {
					if(!fmin) {min =n+1; fmin = true;}
					min = Math.max(min,n+1); 
				}
				else {
					if(!fmax) {max = n; fmax = true;}
					max = Math.min(max,n); 
				}
			}			
			else {
				if(f) {
					if(!fmin){min = n; fmin = true;}
					min = Math.max(min,n);
				}
				else {
					if(!fmax) {max = n-1; fmax = true;}
					max = Math.min(max, n-1);
				}
			}
		}
		//System.out.println(min + " " + max);
		if(!fmax) System.out.println(min+1);
		else if(!fmin) System.out.println(max-1);
		else if(max < min) System.out.println("Impossible");
		else System.out.println(max);
	}
}