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.util.*;



public class Task{
    public static void main(String[] args) throws IOException{
        new Task().run();
    }
    
    StreamTokenizer in; 
    Scanner ins;
    PrintWriter out;

    int nextInt() throws IOException{
        in.nextToken();      
        return (int)in.nval;
    }
    
    long nextLong() throws IOException{
        in.nextToken();      
        return (long)in.nval;
    }
    
    double nextDouble() throws IOException{
        in.nextToken();      
        return in.nval;
    }
    
    char nextChar() throws IOException{
        in.nextToken();
        return (char)in.ttype;
    }
    
    boolean isNextChar() throws IOException{
        in.nextToken();
        return in.ttype != StreamTokenizer.TT_NUMBER;
    }
    
    int getReadedInt(){
        return (int) in.nval;
    }
    
    String nextString() throws IOException{
        in.nextToken();
        return in.sval;
    }
     
    private static final String INPUT = "g.in";    
       
    void run() throws IOException{        
        in = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
        ins = new Scanner(System.in);        
        out = new PrintWriter(System.out);        
        
        try{
            if(System.getProperty("xDx") != null){
                in = new StreamTokenizer(new BufferedReader(new FileReader("input.txt")));
                ins = new Scanner(new FileReader("input.txt"));
                out = new PrintWriter(new FileWriter("output.txt"));
            }else{
//                in = new StreamTokenizer(new BufferedReader(new FileReader(INPUT)));
//                ins = new Scanner(new FileReader(INPUT));
//                out = new PrintWriter(System.out);
            }
        }catch(Exception e){
//            in = new StreamTokenizer(new BufferedReader(new FileReader(INPUT)));
//            ins = new Scanner(new FileReader(INPUT));
//            out = new PrintWriter(System.out);
        }
        
        int n = nextInt();
        int l = -2000000000;
        int r = 2000000000;
        for(int i = 0; i < n; i++){
            char c = nextChar();
            boolean eq = isNextChar();
            int x;
            if(eq){
                x = nextInt();
            }else{
                x = getReadedInt();
            }
            String answ = nextString();
            if("N".equals(answ)){
                eq = !eq;
                c = c == '<' ? '>' : '<';
            }            
            if(c == '<'){            
                if(!eq){
                    --x;
                }
                if(x < r){
                   r = x;
                }
            }else{                
                if(!eq){
                    ++x;
                }
                if(x > l){
                    l = x;
                }
            }
            if(l > r){
                out.print("Impossible");
                break;
            }
        }
        if(l <= r){
            out.print(l);
        }
        out.close();
    }   

}