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:
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;

public class Main {

    public static void main(String[] args) throws Exception {
        try (BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
             BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(System.out))) {
            int rows = Integer.parseInt(reader.readLine());
            int min = -2_000_000_000;
            int max = 2_000_000_000;

            for (int i = 0; i < rows; i++) {
                String text = reader.readLine();
                String[] data = text.split(" ");
                if (data.length != 3) {
                    writer.write("You sucks 1\n");
                    System.exit(-1);
                }
                int val = Integer.parseInt(data[1]);
                if (val < -1_000_000_000 || val > 1_000_000_000) {
                    writer.write("You sucks 2\n");
                    System.exit(-1);
                }
                boolean result = "Y".equalsIgnoreCase(data[2]);
                if (">=".equals(data[0])) {
                    if (result) {
                        min = Math.max(val, min);
                    } else {
                        max = Math.min(val-1, max);
                    }
                } else if (">".equals(data[0])) {
                    if (result) {
                        min = Math.max(val + 1, min);
                    } else {
                        max = Math.min(val, max);
                    }
                } else if ("<".equals(data[0])) {
                    if (!result) {
                        min = Math.max(val, min);
                    } else {
                        max = Math.min(val-1, max);
                    }
                } else if ("<=".equals(data[0])) {
                    if (!result) {
                        min = Math.max(val + 1, min);
                    } else {
                        max = Math.min(val, max);
                    }
                } else {
                    writer.write("You sucks 3\n");
                    System.exit(-1);
                }
            }
            if (min > max) {
                writer.write("Impossible\n");
            } else {
                writer.write(min + "\n");
            }
        }
    }
}