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 main() {
  int n, y, res = 10000000;
  string con;
  char re;
  cin >> n;
  vector<vector<int> > x((n), vector<int>(3));
  for (int i = 0; i < n; ++i) {
    cin >> con >> y >> re;
    if (con == ">=") {
      x[i][0] = 1;
      x[i][1] = y;
      if (re == 'Y')
        x[i][2] = 1;
      else
        x[i][2] = 0;
    }
    if (con == "<") {
      x[i][0] = 2;
      x[i][1] = y;
      if (re == 'Y')
        x[i][2] = 1;
      else
        x[i][2] = 0;
    }
    if (con == "<=") {
      x[i][0] = 3;
      x[i][1] = y;
      if (re == 'Y')
        x[i][2] = 1;
      else
        x[i][2] = 0;
    }
    if (con == ">") {
      x[i][0] = 4;
      x[i][1] = y;
      if (re == 'Y')
        x[i][2] = 1;
      else
        x[i][2] = 0;
    }
  }
  for (int i = 0; i < n; ++i) {
    if (x[i][2] == 1) {
      if (x[i][0] == 1) res = x[i][1];
      if (x[i][0] == 2) res = x[i][1] - 1;
      if (x[i][0] == 3) res = x[i][1];
      if (x[i][0] == 4) res = x[i][1] + 1;
    }
    if (x[i][2] == 0) {
      if (x[i][0] == 1) res = x[i][1] - 1;
      if (x[i][0] == 2) res = x[i][1];
      if (x[i][0] == 3) res = x[i][1] + 1;
      if (x[i][0] == 4) res = x[i][1] - 1;
    }
    int t = 0;
    for (int i = 0; i < n; ++i) {
      if (x[i][2] == 1) {
        if (x[i][0] == 1) {
          if (res >= x[i][1])
            t++;
          else
            break;
        }
        if (x[i][0] == 2) {
          if (res < x[i][1])
            t++;
          else
            break;
        }
        if (x[i][0] == 3) {
          if (res <= x[i][1])
            t++;
          else
            break;
        }
        if (x[i][0] == 4) {
          if (res > x[i][1])
            t++;
          else
            break;
        }
      }
      if (x[i][2] == 0) {
        if (x[i][0] == 1) {
          if (res < x[i][1])
            t++;
          else
            break;
        }
        if (x[i][0] == 2) {
          if (res >= x[i][1])
            t++;
          else
            break;
        }
        if (x[i][0] == 3) {
          if (res > x[i][1])
            t++;
          else
            break;
        }
        if (x[i][0] == 4) {
          if (res <= x[i][1])
            t++;
          else
            break;
        }
      }
    }
    if (t == n) {
      cout << res;
      return 0;
    }
  }
  cout << "Impossible";
  return 0;
}