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;
const int N = 10000;
int a[N];
string s[N];
string b;
char t;
int main() {
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> b >> a[i] >> t;
    if (t == 'Y')
      s[i] = b;
    else if (b == "<=")
      s[i] = ">";
    else if (b == ">=")
      s[i] = "<";
    else if (b == "<")
      s[i] = ">=";
    else if (b == ">")
      s[i] = "<=";
  }
  long long high = 2e9;
  long long low = -2e9;
  long long nh, nl;
  nh = high;
  nl = low;
  int r = 0;
  long long w;
  for (int i = 0; i < n; i++) {
    if (s[i] == ">=") {
      nl = a[i];
    } else if (s[i] == "<=") {
      nh = a[i];
    } else if (s[i] == ">") {
      nl = a[i] + 1;
    } else if (s[i] == "<") {
      nh = a[i] - 1;
    }
    if (nh < low || nl > high) {
      r = 1;
      break;
    } else if (nh == high && nl > low) {
      low = nl;
    } else if (nl == low && nh < high) {
      high = nh;
    } else {
      nl = low;
      nh = high;
    }
  }
  if (r == 1)
    cout << "Impossible" << endl;
  else
    cout << low << endl;
  return 0;
}