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;

public class GuessAnumber {

    public GuessAnumber() throws IOException {
        BufferedReader rd = new BufferedReader(new InputStreamReader(System.in));
        String h = rd.readLine();
        int n = Integer.parseInt(h);
        int min = -2000000000;
        int max = -min;
        for(int i=0;i<n;i++) {
            h = rd.readLine();
            String[] t = h.split("\\s+");
            int k = Integer.parseInt(t[1]);
            char c = t[2].charAt(0);
            if(c == 'N') {
                switch(t[0]) {
                    case ">=":
                        t[0] = "<";
                        break;
                    case ">":
                        t[0] = "<=";
                        break;
                    case "<=":
                        t[0] = ">";
                        break;
                    case "<":
                        t[0] = ">=";
                        break;
                }
            }
            switch(t[0]) {
                case ">=":
                    min = Math.max(min,k);
                    break;
                case ">":
                    min = Math.max(min,k+1);
                    break;
                case "<=":
                    max = Math.min(max,k);
                    break;
                case "<":
                    max = Math.min(max,k-1);
                    break;
            }
        }
        if(min <= max) {
            out(min);
        } else {
            out("Impossible");
        }
    }

    private static void out(Object x) {
        System.out.println(x);
    }

    public static void main(String[] args) throws IOException {
        new GuessAnumber();
    }
}