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>
long long h = 2000000000 + 10, l = -h, ans, mid;
using namespace std;
int main() {
  int n, k;
  scanf("%d", &n);
  char str[10], t[10];
  for (int i = int(0); i < int(n); i++) {
    memset(str, 0, sizeof(str));
    scanf("%s", str);
    scanf("%I64d", &mid);
    scanf("%s", t);
    if (str[0] == '>') {
      if (str[1] == '=') {
        if (t[0] == 'Y')
          k = 1;
        else
          k = 2;
      } else {
        if (t[0] == 'Y')
          k = 3;
        else
          k = 4;
      }
    } else {
      if (str[1] == '=') {
        if (t[0] == 'Y')
          k = 4;
        else
          k = 3;
      } else {
        if (t[0] == 'Y')
          k = 2;
        else
          k = 1;
      }
    }
    switch (k) {
      case 1:
        l = max(l, mid);
        break;
      case 2:
        h = min(h, mid - 1);
        break;
      case 3:
        l = max(l, mid + 1);
        break;
      case 4:
        h = min(h, mid);
        break;
    }
  }
  if (h >= l)
    printf("%d\n", (h + l) >> 1);
  else
    printf("Impossible\n");
  return 0;
}