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;
const long long INF = 2000000000;
const int MOD = 1000000007;
const int MAX_N = 10005;
struct node {
  int type;
  long long x;
} seg[MAX_N];
bool cmp(node a, node b) { return a.x < b.x; }
int main() {
  int n;
  while (cin >> n) {
    char op[5], anw[5];
    int x;
    for (int i = 0; i < n; i++) {
      cin >> op >> x >> anw;
      seg[i].x = x;
      if (strcmp(op, ">=") == 0) {
        if (anw[0] == 'Y') {
          seg[i].type = 1;
        } else {
          seg[i].x--;
          seg[i].type = -1;
        }
      } else if (strcmp(op, "<=") == 0) {
        if (anw[0] == 'Y') {
          seg[i].type = -1;
        } else {
          seg[i].x++;
          seg[i].type = 1;
        }
      } else if (strcmp(op, ">") == 0) {
        if (anw[0] == 'Y') {
          seg[i].x++;
          seg[i].type = 1;
        } else {
          seg[i].type = -1;
        }
      } else {
        if (anw[0] == 'Y') {
          seg[i].type = -1;
          seg[i].x--;
        } else {
          seg[i].type = 1;
        }
      }
    }
    sort(seg, seg + n, cmp);
    int cur = 1;
    long long maxL = -INF, minR = INF;
    bool flag = true;
    for (int i = 0; i < n; i++) {
      if (cur < seg[i].type) {
        flag = false;
        break;
      }
      if (seg[i].type == 1) {
        maxL = max(maxL, seg[i].x);
      } else {
        minR = min(minR, seg[i].x);
      }
    }
    if (!flag || maxL > minR) {
      cout << "Impossible" << endl;
    } else {
      cout << maxL << endl;
    }
  }
  return 0;
}