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 JAVA):

Solution:
function main()
{
    var n = parseInt(readline());
    var up = 1<<30;
    var low = -up;
    while ( n-- )
    {
        var tmp = readline().split(" ");
        tmp[1] = parseInt(tmp[1]);
        if ( tmp[2] == "N" )
        {
            if ( tmp[0] == ">=" )
            {
                tmp[0] = "<";
            }
            else if ( tmp[0] == "<=" )
            {
                tmp[0] = ">";
            }
            else if ( tmp[0] == ">" )
            {
                tmp[0] = "<=";
            }
            else if ( tmp[0] == "<" )
            {
                tmp[0] = ">=";
            }
        }
        if ( tmp[0] == ">" && tmp[1]+1 > low )
        {
                low = tmp[1]+1;
        }
        else if ( tmp[0] == ">=" && tmp[1] > low )
        {
                low = tmp[1];
        }
        else if ( tmp[0] == "<" && tmp[1]-1 < up )
        {
                up = tmp[1]-1;
        }
        else if ( tmp[0] == "<=" && tmp[1] < up )
        {
                up = tmp[1];
        }
    }
    if ( up < low )
    {
        print("Impossible");
    }
    else
    {
        print(low);
    }
}

main();