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 n;
  scanf("%d\n", &n);
  int l = -2000000000, r = 2000000000;
  while (n--) {
    int k = 0;
    char ch;
    int sum = 0, z = 1;
    bool ok = 1;
    while ((ch = getchar()) != '\n') {
      if (ch == ' ') continue;
      if (ch == '>')
        k = 1;
      else if (ch == '<')
        k = 2;
      else if (ch == '=')
        k = k * 10;
      else if (ch == '-')
        z = -1;
      else if (ch >= '0' && ch <= '9')
        sum = sum * 10 + ch - '0';
      else if (ch == 'N')
        ok = 0;
    }
    sum *= z;
    if (k == 1) {
      if (ok && l < sum + 1)
        l = sum + 1;
      else if (!ok && r > sum)
        r = sum;
    } else if (k == 2) {
      if (ok && r > sum - 1)
        r = sum - 1;
      else if (!ok && l < sum)
        l = sum;
    } else if (k == 10) {
      if (ok && l < sum)
        l = sum;
      else if (!ok && r > sum - 1)
        r = sum - 1;
    } else if (k == 20) {
      if (ok && r > sum)
        r = sum;
      else if (!ok && l < sum + 1)
        l = sum + 1;
    }
    if (l > r) {
      printf("Impossible\n");
      return 0;
    }
  }
  printf("%d\n", r);
  return 0;
}