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


signs = ['>=', '>', '<=', '<']
rev_signs = list(reversed(signs))
lower = -pow(10, 9) * 2
upper = -lower


def invert(sign):
    return rev_signs[signs.index(sign)]


def construct(sign, num):
    ceiling = num - int('=' not in sign) if '<' in sign else upper
    floor = num + int('=' not in sign) if '>' in sign else lower
    return (floor, ceiling)


def is_valid(interval):
    return interval[0] <= interval[1]


def intersects(a, b):
    return not (a[1] < b[0] or b[1] < a[0])


def intersect(a, b):
    return (max(a[0], b[0]), min(a[1], b[1]))


def main():
    num_lines = int(sys.stdin.readline().strip())
    bounds = (lower, upper)
    for i in xrange(num_lines):
        input_tokens = sys.stdin.readline().strip().split()
        num = int(input_tokens[1])
        yes = True if input_tokens[2] == 'Y' else False
        sign = input_tokens[0] if yes else invert(input_tokens[0])
        update_bound = construct(sign, num)
        if not is_valid(update_bound):
            print 'Impossible'
            sys.exit(0)
        elif not intersects(update_bound, bounds):
            print 'Impossible'
            sys.exit(0)
        else:
            bounds = intersect(update_bound, bounds)
    print bounds[0]
            
if __name__ == '__main__':
    main()