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 n, m, t, k;
long long l[10005], r[10005];
int x[10005];
char s1[10005][11], s2[10005][11];
int main() {
  scanf("%d", &n);
  long long lx = -2 * 1000000000, ly = 2 * 1000000000;
  l[0] = -2 * 1000000000;
  r[0] = 2 * 1000000000;
  int flag = 1;
  for (int i = 1; i <= n; i++) {
    scanf("%s%d%s", s1[i], &x[i], s2[i]);
    if (s2[i][0] == 'N') {
      if (s1[i][0] == '<') {
        s1[i][0] = '>';
        if (s1[i][1] == '=')
          s1[i][1] = '\0';
        else
          s1[i][1] = '=';
      } else {
        if (s1[i][0] == '>') {
          s1[i][0] = '<';
          if (s1[i][1] == '=')
            s1[i][1] = '\0';
          else
            s1[i][1] = '=';
        }
      }
    }
    if (s1[i][0] == '<' && s1[i][1] == '=') {
      l[i] = l[i - 1];
      r[i] = x[i];
    }
    if (s1[i][0] == '<' && s1[i][1] != '=') {
      l[i] = l[i - 1];
      r[i] = x[i] - 1;
    }
    if (s1[i][0] == '>' && s1[i][1] == '=') {
      r[i] = r[i - 1];
      l[i] = x[i];
    }
    if (s1[i][0] == '>' && s1[i][1] != '=') {
      r[i] = r[i - 1];
      l[i] = x[i] + 1;
    }
    if (l[i] > r[i]) flag = 0;
    lx = max(lx, l[i]);
    ly = min(ly, r[i]);
  }
  if (lx > ly) flag = 0;
  if (flag) {
    printf("%I64d\n", lx);
  } else
    printf("Impossible\n");
  return 0;
}