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:

def process(count, index, num, flag):
    if flag[index] == 0:
        count[index] = num
    else:
        if index == 0 or index == 1:
            if num > count[index]:
                count[index] = num
        else:
            if num < count[index]:
                count[index] = num
    flag[index] = 1

def main():
    n = raw_input()
    n = int(n)
    count = [0,0,0,0]
    flag = [0,0,0,0]

    for i in range(n):
        line = raw_input()
        line = line.split()
        if (line[0] == '>' and line[2] == 'Y') or (line[0] == '<=' and line[2] == 'N'):
            process(count, 0, int(line[1]), flag)
        elif (line[0] == '>' and line[2] == 'N') or (line[0] == '<=' and line[2] == 'Y'):
            process(count, 3, int(line[1]), flag)
        elif (line[0] == '>=' and line[2] == 'Y') or (line[0] == '<' and line[2] == 'N'):
            process(count, 1, int(line[1]), flag)
        elif (line[0] == '>=' and line[2] == 'N') or (line[0] == '<' and line[2] == 'Y'):
            process(count, 2, int(line[1]), flag)

    flag1 = -1
    flag2 = -1
    if (flag[0] != 0 and flag[1] != 0 and count[0] >= count[1]) or (flag[0] != 0 and flag[1] == 0):
        flag1 = 0
    elif (flag[0] != 0 and flag[1] != 0 and count[0] < count[1]) or (flag[0] == 0 and flag[1] != 0):
        flag1 = 1

    if (flag[2] != 0 and flag[3] != 0 and count[2] <= count[3]) or (flag[2] != 0 and flag[3] == 0):
        flag2 = 2
    elif (flag[2] != 0 and flag[3] != 0 and count[2] > count[3]) or (flag[2] == 0 and flag[3] != 0):
        flag2 = 3
    
    
    if flag1 == -1 and flag2 == -1:
        print 'Impossible'
    elif flag1 == -1 and flag2 != -1:
        print count[flag2] - 1
    elif flag2 == -1 and flag1 != -1:
        print count[flag1] + 1
    elif count[flag1] > count[flag2]:
        print 'Impossible'
    elif count[flag1] == count[flag2]:
        if flag1 == 1 and flag2 == 3:
            print count[flag1]
        else:
            print 'Impossible'
    else:
        if count[flag2] - count[flag1] > 1:
            print count[flag1] + (count[flag2] - count[flag1] + 1)/2
        else:
            if flag1 == 0 and flag2 == 2:
                print 'Impossible'
            elif flag1 == 1 and flag2 == 2:
                print count[flag1]
            elif flag1 == 0 and flag2 == 3:
                print count[flag2]
            elif flag1 == 1 and flag2 == 3:
                print count[flag1]

if __name__ == '__main__':
    main()