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 mi = -2000000000;
  int ma = 2000000000;
  vector<int> v;
  vector<pair<int, int> > p;
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) p.push_back(make_pair(mi, ma));
  string arr[n], ar[n];
  int i, a[n];
  for (i = 0; i < n; i++) {
    cin >> arr[i];
    cin >> a[i];
    cin >> ar[i];
    if (arr[i] == "<=" && ar[i] == "Y")
      p[i].second = a[i];
    else if (arr[i] == "<=" && ar[i] == "N")
      p[i].first = a[i] + 1;
    else if (arr[i] == "<" && ar[i] == "Y")
      p[i].second = a[i] - 1;
    else if (arr[i] == "<" && ar[i] == "N")
      p[i].first = a[i];
    else if (arr[i] == ">=" && ar[i] == "Y")
      p[i].first = a[i];
    else if (arr[i] == ">=" && ar[i] == "N")
      p[i].second = a[i] - 1;
    else if (arr[i] == ">" && ar[i] == "Y")
      p[i].first = a[i] + 1;
    else if (arr[i] == ">" && ar[i] == "N")
      p[i].second = a[i];
  }
  sort(p.begin(), p.end());
  int k = p[p.size() - 1].first;
  for (i = 0; i < p.size(); i++) v.push_back(p[i].second);
  sort(v.begin(), v.end());
  int t = v[0];
  if (t >= k)
    cout << k;
  else
    cout << "Impossible";
  return 0;
}