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;
int flag = 0;
void wrong() { flag = 1; }
string set_sign(string sign, string ans) {
  if (sign == ">=") {
    if (ans == "N") sign = "<";
  } else if (sign == "<") {
    if (ans == "N") sign = ">=";
  } else if (sign == ">") {
    if (ans == "N") sign = "<=";
  } else if (sign == "<=") {
    if (ans == "N") sign = ">";
  }
  return sign;
}
int main() {
  int n, begin = -2000000000, end = 2000000000;
  cin >> n;
  for (int i = 0; i < n; i++) {
    int x;
    string sign, ans;
    cin >> sign >> x >> ans;
    sign = set_sign(sign, ans);
    if (sign == "<") {
      if (x <= begin) wrong();
      if (x <= end) {
        end = x - 1;
      }
      if (end < begin) wrong();
    } else if (sign == ">") {
      if (x >= end) wrong();
      if (x >= begin) {
        begin = x + 1;
      }
      if (begin > end) wrong();
    } else if (sign == "<=") {
      if (x < begin) wrong();
      if (x < end) {
        end = x;
      }
      if (begin > end) wrong();
    } else if (sign == ">=") {
      if (x > end) wrong();
      if (x > begin) {
        begin = x;
      }
      if (begin > end) wrong();
    }
  }
  if (flag)
    cout << "Impossible" << endl;
  else
    cout << begin << endl;
  return 0;
}