CF416A.Guess a number!

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".

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 $-10^{9}<=x<=10^{9}$ . The answer is an English letter "Y" (for "yes") or "N" (for "no").

Consequtive elements in lines are separated by a single space.

Print any of such integers $y$ , that the answers to all the queries are correct. The printed number $y$ must meet the inequation $-2·10^{9}<=y<=2·10^{9}$ . If there are many answers, print any of them. If such value doesn't exist, print word "Impossible" (without the quotes).