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;
struct Statement {
  int value;
  string op;
  char judge;
};
struct Scope {
  int from;
  int to;
};
string getOp(string str, char judge) {
  if (judge == 'Y') return str;
  if (str == ">") return "<=";
  if (str == ">=") return "<";
  if (str == "<") return ">=";
  if (str == "<=") return ">";
  return "";
}
bool eval(string op, int limit, Scope &possible) {
  if (op == ">") {
    if (limit < possible.from) return true;
    if (limit >= possible.to) return false;
    possible.from = limit + 1;
    return true;
  }
  if (op == ">=") {
    if (limit < possible.from) return true;
    if (limit > possible.to) return false;
    possible.from = limit;
    return true;
  }
  if (op == "<") {
    if (limit > possible.to) return true;
    if (limit <= possible.from) return false;
    possible.to = limit - 1;
    return true;
  }
  if (op == "<=") {
    if (limit > possible.to) return true;
    if (limit < possible.from) return false;
    possible.to = limit;
    return true;
  }
  return false;
}
int main() {
  int N;
  cin >> N;
  vector<Statement> states(N);
  for (int i = 0; i < N; i++) {
    cin >> states[i].op >> states[i].value >> states[i].judge;
  }
  Scope possible;
  possible.from = -2000000000;
  possible.to = 2000000000;
  bool found = true;
  for (int i = 0; i < N; i++) {
    if (!eval(getOp(states[i].op, states[i].judge), states[i].value,
              possible)) {
      found = false;
      break;
    }
  }
  if (!found || possible.from > possible.to) {
    cout << "Impossible" << endl;
  } else {
    cout << possible.from << endl;
  }
  return 0;
}