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 i, n, x, d, u;
  char ans, q[10], line[100];
  bool checkd = false, checku = false;
  scanf("%d", &n);
  gets(line);
  for (i = 1; i <= n; i++) {
    gets(line);
    sscanf(line, "%s %d %c", &q, &x, &ans);
    if (ans == 'Y') {
      if (strlen(q) == 1) {
        if (q[0] == '>') {
          if (checkd)
            d = max(d, x + 1);
          else {
            d = x + 1;
            checkd = true;
          }
        } else {
          if (checku)
            u = min(u, x - 1);
          else {
            u = x - 1;
            checku = true;
          }
        }
      } else {
        if (q[0] == '>') {
          if (checkd)
            d = max(d, x);
          else {
            d = x;
            checkd = true;
          }
        } else {
          if (checku)
            u = min(u, x);
          else {
            u = x;
            checku = true;
          }
        }
      }
    } else {
      if (strlen(q) == 1) {
        if (q[0] == '>') {
          if (checku)
            u = min(u, x);
          else {
            u = x;
            checku = true;
          }
        } else {
          if (checkd)
            d = max(d, x);
          else {
            d = x;
            checkd = true;
          }
        }
      } else {
        if (q[0] == '>') {
          if (checku)
            u = min(u, x - 1);
          else {
            u = x - 1;
            checku = true;
          }
        } else {
          if (checkd)
            d = max(d, x + 1);
          else {
            d = x + 1;
            checkd = true;
          }
        }
      }
    }
  }
  if (d > u && checku && checkd)
    printf("Impossible");
  else if (checkd)
    printf("%d", d);
  else if (checku)
    printf("%d", u);
  else
    printf("0");
}