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 PYTHON):

Solution:
import sys,math

types    = ['<=','>=' ,'<' ,'>'  ]
opposite = [ '>','<' ,'>=' ,'<=' ]

def update(big,small,value):
	
	# fix assertion
	if value[2] != 'Y':	
		value[0] = opposite[types.index(value[0])]
	
	# fix strictness 
	action = types.index(value[0])
	if action < 2 : 	
		value[1] = str(int(value[1])+1) if action == 0 else str(int(value[1])-1)
	
	# merge constraints	
	if action == 0 or action == 2: # less
		big = min(big,int(value[1]))
	else:
		small = max(small,int(value[1]))

	return big,small
		

if __name__ == '__main__':
	input = int(raw_input())
	big, small = float('inf'),-float('inf')
	for i in range(input):
		big,small = update(big,small,raw_input().split())

	if big - small >= 2:
		print small + 1 if small != -float('inf') else big - 1
	else:
		print 'Impossible'