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 JAVA):

Solution:

import java.io.*;
import java.math.BigInteger;
import java.util.*;

public class Main {
  public static void main(String[] args) throws Exception {
        Reader.init(System.in);
       int n=Reader.nextInt();
       String a[]=new String [n];
     int s=-2000000000,e =2000000000;
       for (int i = 0; i < a.length; i++)
      {
          a[i]=Reader.reader.readLine();
          String b="";
          if(a[i].startsWith(">")&&a[i].charAt(a[i].length()-1)=='Y')
          { 
              if(a[i].startsWith(">="))
          s=Math.max(s, Integer.valueOf(a[i].substring(2,a[i].length()-2).trim()));
              else
          s=Math.max(s, Integer.valueOf(a[i].substring(1,a[i].length()-2).trim())+1);
                     
          }
          else
              if(a[i].startsWith("<")&&a[i].charAt(a[i].length()-1)=='N')
              { 
                   if(a[i].startsWith("<="))
          s=Math.max(s, Integer.valueOf(a[i].substring(2,a[i].length()-2).trim())+1);
              else
          s=Math.max(s, Integer.valueOf(a[i].substring(1,a[i].length()-2).trim()));
            
              }
          else
              if(a[i].startsWith(">")&&a[i].charAt(a[i].length()-1)=='N')
              { 
                   if(a[i].startsWith(">="))
          e=Math.min(e, Integer.valueOf(a[i].substring(2,a[i].length()-2).trim())-1);
              else
          e=Math.min(e, Integer.valueOf(a[i].substring(1,a[i].length()-2).trim()));
            
              }
           else
              if(a[i].startsWith("<")&&a[i].charAt(a[i].length()-1)=='Y')
              {
                   if(a[i].startsWith("<="))
          e=Math.min(e, Integer.valueOf(a[i].substring(2,a[i].length()-2).trim()));
              else
          e=Math.min(e, Integer.valueOf(a[i].substring(1,a[i].length()-2).trim())-1);
            
              }
      
      }
      System.out.println(s>e?"Impossible":s);
      
  }
}
class Reader {

    static BufferedReader reader;
    static StringTokenizer tokenizer;

    /**
     * call this method to initialize reader for InputStream
     */
    static void init(InputStream input) {
        reader = new BufferedReader(
                new InputStreamReader(input));
        tokenizer = new StringTokenizer("");
    }

    /**
     * get next word
     */
    static String next() throws IOException {
        while (!tokenizer.hasMoreTokens()) {
            //TODO add check for eof if necessary
            tokenizer = new StringTokenizer(
                    reader.readLine());
        }
        return tokenizer.nextToken();
    }

    static int nextInt() throws IOException {
        return Integer.parseInt(next());
    }

    static long nextLong() throws IOException {
        return Long.parseLong(next());
    }

    static double nextDouble() throws IOException {
        return Double.parseDouble(next());
    }

    static public void nextIntArrays(int[]... arrays) throws IOException {
        for (int i = 1; i < arrays.length; ++i) {
            if (arrays[i].length != arrays[0].length) {
                throw new InputMismatchException("Lengths are different");
            }
        }
        for (int i = 0; i < arrays[0].length; ++i) {
            for (int[] array : arrays) {
                array[i] = nextInt();
            }
        }
    }

    static public void nextLineArrays(String[]... arrays) throws IOException {
        for (int i = 1; i < arrays.length; ++i) {
            if (arrays[i].length != arrays[0].length) {
                throw new InputMismatchException("Lengths are different");
            }
        }
        for (int i = 0; i < arrays[0].length; ++i) {
            for (String[] array : arrays) {
                array[i] = reader.readLine();
            }
        }
    }
}