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.*;
import java.util.*;

public class Main {
    static int min = Integer.MIN_VALUE, max = Integer.MAX_VALUE;

    public static void main(String[] args) {
        FastReader fr = new FastReader();
        int n = fr.nextInt();
        while (n-- > 0) {
            String[] query = fr.nextLine().split(" ");
            switch (query[0]) {
                case ">=":
                    if (query[2].equals("Y")) {
                        min = Math.max(min, Integer.parseInt(query[1]));
                    } else {
                        max = Math.min(max, Integer.parseInt(query[1]) - 1);
                    }
                    break;
                case ">":
                    if (query[2].equals("Y")) {
                        min = Math.max(min, Integer.parseInt(query[1]) + 1);
                    } else {
                        max = Math.min(max, Integer.parseInt(query[1]));
                    }
                    break;
                case "<=":
                    if (query[2].equals("Y")) {
                        max = Math.min(max, Integer.parseInt(query[1]));
                    } else {
                        min = Math.max(min, Integer.parseInt(query[1]) + 1);
                    }
                    break;
                case "<":
                    if (query[2].equals("Y")) {
                        max = Math.min(max, Integer.parseInt(query[1]) - 1);
                    } else {
                        min = Math.max(min, Integer.parseInt(query[1]));
                    }
                    break;
            }

        }
        int answer = findAnswer(min, max);
        if (answer == Integer.MAX_VALUE)
            System.out.println("Impossible");
        else
            System.out.println(answer);

    }

    private static int findAnswer(long min, long max) {
        if (min > max)
            return Integer.MAX_VALUE;

        int answer = (int) ((min + max) >> 1);
        if (answer > Math.pow(2 * 10, 9)) {
            return Integer.MAX_VALUE;
        }
        if (answer < Math.pow(-2 * 10, 9)) {
            return Integer.MAX_VALUE;
        }
        return answer;

    }
}

class FastReader {
    private BufferedReader br;
    private StringTokenizer st;

    public FastReader() {
        br = new BufferedReader(new InputStreamReader(System.in));
    }

    public String next() {
        while (st == null || !st.hasMoreElements()) {
            try {
                st = new StringTokenizer(br.readLine());
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return st.nextToken();
    }

    public int nextInt() {
        return Integer.parseInt(next());
    }

    public long nextLong() {
        return Long.parseLong(next());
    }

    public double nextDouble() {
        return Double.parseDouble(next());
    }

    public String nextLine() {
        String str = "";
        try {
            str = br.readLine();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return str;
    }
}