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() {
  string str;
  int lower = -2000000000, higher = 2000000000;
  int lower_stat = 1, higher_stat = 1;
  int n, i, num;
  bool lt, le, gt, ge, imposs = false;
  char c;
  scanf("%d", &n);
  while (n--) {
    lt = le = gt = ge = false;
    cin >> str >> num >> c;
    if (imposs) continue;
    if (c == 'N') {
      if (str.compare(">=") == 0)
        lt = true;
      else if (str.compare(">") == 0)
        le = true;
      else if (str.compare("<") == 0)
        ge = true;
      else
        gt = true;
    } else {
      if (str.compare(">=") == 0)
        ge = true;
      else if (str.compare(">") == 0)
        gt = true;
      else if (str.compare("<") == 0)
        lt = true;
      else
        le = true;
    }
    if (ge) {
      if (num > lower) {
        lower = num;
        lower_stat = 1;
      }
    } else if (gt) {
      if (num > lower) {
        lower = num;
        lower_stat = 0;
      } else if (num == lower) {
        lower_stat = 0;
      }
    } else if (le) {
      if (num < higher) {
        higher = num;
        higher_stat = 1;
      }
    } else if (lt) {
      if (num < higher) {
        higher = num;
        higher_stat = 0;
      }
      higher_stat = 0;
    }
    if (lower > higher) {
      imposs = true;
    } else if (lower == higher) {
      if (lower_stat + higher_stat <= 1) {
        imposs = true;
      }
    } else if ((higher - lower == 1) && higher_stat == 0 && lower_stat == 0) {
      imposs = true;
    }
  }
  if (imposs) {
    printf("Impossible\n");
    return 0;
  }
  if (lower_stat == 1)
    printf("%d\n", lower);
  else if (higher_stat == 1)
    printf("%d\n", higher);
  else
    printf("%d\n", lower + 1);
  return 0;
}