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.InputStreamReader;
import java.util.StringTokenizer;

public class Problem241Div2final {

    static double miny = -(2*Math.pow(10, 9));
    static double maxy = (2*Math.pow(10, 9));

    public static void main(String[] args){

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        try{
            int n= Integer.parseInt(br.readLine());

            if(n < 1 || n > 10000){ 
                return;
            }

            for (int i=0;i<n;i++){
                String line = br.readLine();

                if (line == null || line.trim().equals("")) continue;

                boolean valid = parseLine(line);
                if (!valid) {
                    break;
                }
            }
            
            if(miny< - 2*Math.pow(10, 9) || maxy>2*Math.pow(10, 9)){
                System.out.println("Impossible");
            }
            else if(miny > maxy) System.out.println("Impossible");
            else if(miny == maxy) System.out.println((int)miny);
            else System.out.println((int)miny + 1);


        } catch(Exception e){
            System.out.println("Exception: " + e.getMessage());
        }

    }

    public static boolean parseLine(String input){

        StringTokenizer str = new StringTokenizer(input);
        String symbol = str.nextToken();
        int x = Integer.parseInt(str.nextToken());

        if(x<-Math.pow(10, 9) || x>Math.pow(10, 9)) return false;

        String val = str.nextToken();
        if(val.equals("N")){
            symbol = invertSymbol(symbol);
        }


        switch (symbol) {
        case "<=":
            if(maxy > x)
                maxy = x;
            return true;
        case "<":
            if(maxy >= x)
                maxy = x-1;
            return true;
        case ">=":
            if(miny < x)
                miny = x;
            return true;
        case ">":
            if(miny <= x)
                miny = x+1;
            return true;
        }
        return false;
    }


    public static String invertSymbol(String symbol){

        switch (symbol) {
        case "<=":
            return ">";
        case "<":
            return ">=";
        case ">=":
            return "<";
        case ">":
            return "<=";
        }
        return symbol;
    }
}