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 op(string &s1, char c1) {
  if (s1.size() < 2)
    if (s1[0] == '>')
      s1 = "<=";
    else
      s1 = ">=";
  else if (s1[0] == '>')
    s1 = "<";
  else
    s1 = ">";
}
int main() {
  string s;
  vector<string> v1;
  vector<int> v2;
  bool big = true, pos = true;
  int t, o, n, ans;
  char c;
  cin >> n;
  cin >> s >> t >> c;
  if (c == 'N') op(s, c);
  if (s[0] == '<') big = false;
  if (s.size() > 1)
    ans = t;
  else if (big)
    ans = t + 1;
  else
    ans = t - 1;
  if (big)
    for (int i = 1; i < n; ++i) {
      cin >> s >> t >> c;
      if (c == 'N') op(s, c);
      if (s[0] == '>') {
        if (t >= ans)
          if (s.size() > 1)
            ans = t;
          else
            ans = t + 1;
      } else {
        v1.push_back(s);
        v2.push_back(t);
      }
    }
  else
    for (int i = 1; i < n; ++i) {
      cin >> s >> t >> c;
      if (c == 'N') op(s, c);
      if (s[0] == '<') {
        if (t <= ans)
          if (s.size() > 1)
            ans = t;
          else
            ans = t - 1;
      } else {
        v1.push_back(s);
        v2.push_back(t);
      }
    }
  if (big) {
    for (int i = 0; i < v1.size(); ++i) {
      if (v1[i].size() > 1 && ans > v2[i])
        pos = false;
      else if (v1[i].size() < 2 && ans >= v2[i])
        pos = false;
    }
  } else {
    for (int i = 0; i < v1.size(); ++i) {
      if (v1[i].size() > 1 && ans < v2[i])
        pos = false;
      else if (v1[i].size() < 2 && ans <= v2[i])
        pos = false;
    }
  }
  if (pos)
    cout << ans;
  else
    cout << "Impossible";
}