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.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Task {
    int left = -2 * 1000000000, right = 2 * 1000000000;

    public static void main(String[] args) {
        new Task();
    }

    public Task() {
        MyScanner myscan = new MyScanner();
        int n = myscan.nextInt();

        for (int i = 0; i < n; ++i) {
            String line = myscan.nextLine();
            String[] parts = line.split(" ");

            String comparator = parts[0];
            String result = parts[2];
            int border = Integer.parseInt(parts[1]);

            if (comparator.compareTo(">=") == 0) {
                if (result.compareTo("Y") == 0) {
                    // checking left border
                    modifyBorder(border, 0);
                }
                if (result.compareTo("N") == 0) {
                    // right border
                    modifyBorder(border - 1, 1);
                }
            }

            if (comparator.compareTo("<=") == 0) {
                if (result.compareTo("Y") == 0) {
                    // checking left border
                    modifyBorder(border, 1);
                }
                if (result.compareTo("N") == 0) {
                    // right border
                    modifyBorder(border + 1, 0);
                }
            }

            if (comparator.compareTo(">") == 0) {
                if (result.compareTo("Y") == 0) {
                    // checking left border
                    modifyBorder(border + 1, 0);
                }
                if (result.compareTo("N") == 0) {
                    // right border
                    modifyBorder(border, 1);
                }
            }

            if (comparator.compareTo("<") == 0) {
                if (result.compareTo("Y") == 0) {
                    // checking left border
                    modifyBorder(border - 1, 1);
                }
                if (result.compareTo("N") == 0) {
                    // right border
                    modifyBorder(border, 0);
                }
            }
        }

        if (left <= right)
            System.out.println(left);
        else System.out.println("Impossible");
    }

    public void modifyBorder(int newValue, int position) {
        if (position == 0) {
            // modifying left border
            if (newValue <= left) return;
            else left = newValue;
        }
        if (position == 1) {
            // modifying right border
            if (newValue >= right) return;
            else right = newValue;
        }
    }
}

class MyScanner {
    BufferedReader br;
    StringTokenizer st;

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

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

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

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

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

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

}