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;
void do_nothing() {}
void solve() {
  int n;
  cin >> n;
  long long down = -2 * 1000 * 1000 * 1000;
  long long up = -down;
  for (int(i) = 0; (i) < (n); (i)++) {
    string qu, ans;
    long long val;
    cin >> qu >> val >> ans;
    if (ans == "N") {
      qu[0] = qu[0] == '<' ? '>' : '<';
      if ((int)(qu).size() == 1)
        qu += '=';
      else
        qu = qu[0];
    }
    if (qu == "<") up = min(up, val - 1);
    if (qu == ">") down = max(down, val + 1);
    if (qu == ">=") down = max(down, val);
    if (qu == "<=") up = min(up, val);
  }
  if (down <= up)
    cout << (up + down) / 2 << "\n";
  else
    cout << "Impossible";
}
int main() {
  solve();
  return 0;
}