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 CPP):

Solution:
#include <bits/stdc++.h>
int main(void) {
  int n;
  while (std::cin >> n) {
    int min, max;
    bool minset = false, maxset = false;
    for (int j = 0; j < n; j++) {
      int i;
      std::string a;
      char b;
      std::cin >> a >> i >> b;
      int status;
      if (a == ">=") {
        if (b == 'N')
          status = 4;
        else
          status = 1;
      }
      if (a == ">") {
        if (b == 'N')
          status = 3;
        else
          status = 2;
      }
      if (a == "<=") {
        if (b == 'N')
          status = 2;
        else
          status = 3;
      }
      if (a == "<") {
        if (b == 'N')
          status = 1;
        else
          status = 4;
      }
      if (status == 1) {
        if (minset == false) {
          min = i;
          minset = true;
        } else
          min = std::max(i, min);
      }
      if (status == 2) {
        if (minset == false) {
          min = i + 1;
          minset = true;
        } else
          min = std::max(i + 1, min);
      }
      if (status == 3) {
        if (maxset == false) {
          max = i;
          maxset = true;
        } else
          max = std::min(max, i);
      }
      if (status == 4) {
        if (maxset == false) {
          max = i - 1;
          maxset = true;
        } else
          max = std::min(max, i - 1);
      }
    }
    if (min > max && minset == true && maxset == true)
      std::cout << "Impossible\n";
    else if (minset == false)
      std::cout << max << '\n';
    else
      std::cout << min << '\n';
  }
}