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.ArrayList;
import java.util.Arrays;
import java.util.Collections;

public class Task {
       static BufferedReader br ;
       static PrintWriter out;
       
       static boolean isSpace(int ch){
           return ((ch==10||ch==32)||(ch==9||ch==13));
       }
       
       static int readInt() throws IOException{
           int ret = 0,sign=1;
           int ch = br.read();
           while(isSpace(ch))ch=br.read();
           if(ch==45){sign*=-1;ch=br.read();}
           do{
               ret*=10;
               ret+=(ch-48);
               ch = br.read();
           }while(48<=ch&&ch<=57);
           return sign*ret;
       }
       
       static String readString() throws IOException{
           StringBuffer sb = new StringBuffer();
           int ch = br.read();
           while(isSpace(ch))ch=br.read();
           do{
               sb.append((char) ch);
               ch = br.read();
           }while(!isSpace(ch));
           return sb.toString();
       }
       
       public static void main(String[] args)throws IOException{
           br = new BufferedReader(new InputStreamReader(System.in));
           out = new PrintWriter(System.out);
           int n = readInt();
           int ans = -1;
           boolean poosible = true;
           int[] gt = new int[n+1];
           int[] g = new int[n+1];
           int[] l = new int[n+1];
           int[] lt = new int[n+1];
           int gts,gs,ls,lts;
           gts=gs=ls=lts=0;
           while(n-- > 0){
               String sign = readString();
               int x = readInt();
               String rep = readString();
               if(sign.equals(">=")){
                   if(rep.equals("Y")){
                       gt[++gts]=x;
                   }
                   else l[++ls]=x;
               }
               else if(sign.equals("<=")){
                   if(rep.equals("Y")){
                       lt[++lts]=x;
                   }
                   else g[++gs]=x;
               }
               else if(sign.equals(">")){
                    if(rep.equals("Y"))g[++gs]=x;
                    else lt[++lts]=x;
               }
               else{
                   if(rep.equals("Y"))l[++ls]=x;
                   else gt[++gts]=x;
               }
           }
           Arrays.sort(l,1,ls+1);
           Arrays.sort(g,1,gs+1);
           Arrays.sort(lt,1,lts+1);
           Arrays.sort(gt,1,gts+1);
           long ul,ll;
           ul=2000000000L;
           ll=-1*ul;
           if(ls > 0)ul = Math.min(ul,l[1]-1);
           if(lts > 0)ul = Math.min(ul,lt[1]);
           if(gs > 0)ll = Math.max(ll,g[gs]+1);
           if(gts > 0)ll=Math.max(ll,gt[gts]);
           if(ul-ll+1 >= 1)out.println(ll);
           else out.println("Impossible");
           out.close();
       }
}