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>
using namespace std;
struct guess {
  bool greater;
  bool include_equal;
  int val;
  bool yes;
};
int main() {
  int n;
  cin >> n;
  vector<guess> guesses;
  for (int i = 0; i < n; i++) {
    string stmp;
    int vtmp;
    char atmp;
    cin >> stmp >> vtmp >> atmp;
    guess tmp;
    if (stmp[0] == '>')
      tmp.greater = true;
    else
      tmp.greater = false;
    if (stmp.length() > 1)
      tmp.include_equal = true;
    else
      tmp.include_equal = false;
    if (atmp == 'Y')
      tmp.yes = true;
    else
      tmp.yes = false;
    tmp.val = vtmp;
    guesses.push_back(tmp);
  }
  const int MAX = 2000000000;
  const int MIN = -2000000000;
  int ymin = MIN;
  int ymax = MAX;
  for (int i = 0; i < n; i++) {
    guess current = guesses[i];
    if (current.yes) {
      if (current.greater) {
        if (current.include_equal) {
          ymin = max(ymin, current.val);
        } else {
          ymin = max(ymin, current.val + 1);
        }
      } else {
        if (current.include_equal) {
          ymax = min(ymax, current.val);
        } else {
          ymax = min(ymax, current.val - 1);
        }
      }
    } else {
      if (current.greater) {
        if (current.include_equal) {
          ymax = min(ymax, current.val - 1);
        } else {
          ymax = min(ymax, current.val);
        }
      } else {
        if (current.include_equal) {
          ymin = max(ymin, current.val + 1);
        } else {
          ymin = max(ymin, current.val);
        }
      }
    }
  }
  if (ymin > ymax)
    cout << "Impossible";
  else
    cout << ymin;
  return 0;
}