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 cnt = 0;
  bool flag = true;
  int low = -2000000000, high = 2000000000;
  bool lset = false;
  bool hset = false;
  cin >> cnt;
  for (int i = 1; i <= cnt; i++) {
    string str1, str2, str3;
    cin >> str1 >> str2 >> str3;
    stringstream stream(str2);
    int num;
    stream >> num;
    if (((str1 == ">") && (str3 == "Y")) || ((str1 == "<=") && (str3 == "N"))) {
      if (low <= num) {
        low = num + 1;
        lset = true;
      }
      if (lset && hset && (high < low || low > 2000000000)) {
        flag = false;
        break;
      }
    }
    if (((str1 == ">=") && (str3 == "Y")) || ((str1 == "<") && (str3 == "N"))) {
      if (low < num) {
        low = num;
        lset = true;
      }
      if (lset && hset && (high < low || low > 2000000000)) {
        flag = false;
        break;
      }
    }
    if (((str1 == "<=") && (str3 == "Y")) || ((str1 == ">") && (str3 == "N"))) {
      if (high > num) {
        high = num;
        hset = true;
      }
      if (lset && hset && (high < low || high < -2000000000)) {
        flag = false;
        break;
      }
    }
    if (((str1 == "<") && (str3 == "Y")) || ((str1 == ">=") && (str3 == "N"))) {
      if (high >= num) {
        high = num - 1;
        hset = true;
      }
      if (lset && hset && (high < low || high < -2000000000)) {
        flag = false;
        break;
      }
    }
  }
  if (flag && (!hset) && lset) cout << low << endl;
  if (flag && (!lset) && hset) cout << high << endl;
  if (flag && !lset && !hset) cout << "0" << endl;
  if (flag && lset && hset) cout << low << endl;
  if (!flag) cout << "Impossible" << endl;
}