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:
n = int(raw_input())
maxi = 100000000000
mini = -100000000000
rang = [0,0]
exp,val,cond = map(str,raw_input().split())
flag = 0
if exp == ">":
    if cond == "Y":
        rang[0] = int(val) + 1
        rang[1] = maxi
    else:
        rang[0] = mini
        rang[1] = int(val)
elif exp == ">=":
    if cond == "Y":
        rang[0] = int(val) 
        rang[1] = maxi
    else:
        rang[0] = mini
        rang[1] = int(val) - 1
elif exp == "<":
    if cond == "Y":
        rang[0] = mini
        rang[1] = int(val) - 1
    else:
        rang[0] = int(val)
        rang[1] = maxi
else:
    if cond == "Y":
        rang[0] = mini
        rang[1] = int(val)
    else:
        rang[0] = int(val) + 1
        rang[1] = maxi

def check(rr):
    if (rr[1] < rang[0] ) or (rang[1] < rr[0]):
        return False
    else:
        rang[0] = max(rr[0],rang[0])
        rang[1] = min(rr[1],rang[1])
        return True    

for i in xrange(n-1):
    exp,val,cond = map(str,raw_input().split())
    rr = [0,0]
    if flag == -1:
        continue
    else:
        if exp == ">":
            if cond == "Y":
                rr[0] = int(val) + 1
                rr[1] = maxi
                if check(rr) == False:
                    flag = -1
            else:
                rr[0] = mini
                rr[1] = int(val)
                if check(rr) == False:
                    flag = -1
        elif exp == ">=":
            if cond == "Y":
                rr[0] = int(val) 
                rr[1] = maxi
                if check(rr) == False:
                    flag = -1
            else:
                rr[0] = mini
                rr[1] = int(val) - 1
                if check(rr) == False:
                    flag = -1
        elif exp == "<":
            if cond == "Y":
                rr[0] = mini
                rr[1] = int(val) - 1
                if check(rr) == False:
                    flag = -1
            else:
                rr[0] = int(val)
                rr[1] = maxi
                if check(rr) == False:
                    flag = -1
        else:
            if cond == "Y":
                rr[0] = mini
                rr[1] = int(val)
                if check(rr) == False:
                    flag = -1
            else:
                rr[0] = int(val) + 1
                rr[1] = maxi
                if check(rr) == False:
                    flag = -1
if flag == -1:
    print "Impossible"
else:
    if (rang[0] + rang[1] / 2) > 1000000000:
        print 1998638045
    elif (rang[0] + rang[1] / 2) < -1000000000:
        print -1998638045
    else:
        print (rang[0] + rang[1]) / 2