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

public class Main {

    InputReader ir = new InputReader(System.in);
    PrintWriter out = new PrintWriter(System.out);
    final long kmod = 993960000099397l;
    
    void solve() {
        int n = ir.readInt();
        int l[] = new int[n];
        int r[] = new int[n];
        HashMap <String , String> map = new HashMap();
        map.put(">", "<=");
        map.put("<", ">=");
        map.put("<=", ">");
        map.put(">=", "<");
        int infpos = (int)(2*1e9);
        int infneg = (int)(-2*1e9);
        for(int i = 0; i < n; i++) {
            String cond = ir.readString();
            int num = ir.readInt();
            String bool = ir.readString();
            if(bool.compareTo("N") == 0)
                cond = map.get(cond);
            if(cond.compareTo(">=") == 0) {
                l[i] = num;
                r[i] = infpos;
            } else if(cond.compareTo("<=") == 0){
                l[i] = infneg;
                r[i] = num;
            } else if(cond.compareTo("<") == 0) {
                l[i] = infneg;
                r[i] = num - 1;
            } else {
                l[i] = num + 1;
                r[i] = infpos;
            }
        }

        int left = infneg;
        int right = infpos;
        for(int i = 0; i < n; i++) {

            if(right >= l[i] && left <= r[i]) {
                left = Math.max(left, l[i]);
                right = Math.min(right, r[i]);
            } else {
                //out.println(l[i]+" "+r[i]);
                out.println("Impossible");
                return;
            }
        }

        for(int i = left; i <= right; i++) {
            out.println(i);
            return;
        }
         out.println("Impossible");
         return;
    }

    void run() {
        solve();
        out.close();
    }
    public static void main(String args[]){
        new Main().run();
    }
}

class InputReader {
 
    private InputStream stream;
    private byte[] buf = new byte[1024];
    private int curChar;
    private int numChars;
    private SpaceCharFilter filter;
 
    public InputReader(InputStream stream) {
        this.stream = stream;
    }
 
    public int read() {
        if (numChars == -1)
            throw new InputMismatchException();
        if (curChar >= numChars) {
            curChar = 0;
            try {
                numChars = stream.read(buf);
            } catch (IOException e) {
                throw new InputMismatchException();
            }
            if (numChars <= 0)
                return -1;
        }
        return buf[curChar++];
    }
    public final int readInt() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
    }
    public long readLong() {
        int c = read();
        while (isSpaceChar(c))
            c = read();
        int sgn = 1;
        if (c == '-') {
            sgn = -1;
            c = read();
        }
        long res = 0;
        do {
            if (c < '0' || c > '9')
                throw new InputMismatchException();
            res *= 10;
            res += c - '0';
            c = read();
        } while (!isSpaceChar(c));
        return res * sgn;
    }
 
    public String readString() {
        int c = read();
        while (isSpaceChar(c))
            c = read();
        StringBuilder res = new StringBuilder();
        do {
            res.appendCodePoint(c);
            c = read();
        } while (!isSpaceChar(c));
        return res.toString();
    }
 
    public boolean isSpaceChar(int c) {
        if (filter != null)
            return filter.isSpaceChar(c);
        return isWhitespace(c);
    }
        public double readDouble() {
        return Double.parseDouble(readString());
    }
 
    public static boolean isWhitespace(int c) {
        return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
    }
 
    public String next() {
        return readString();
    }
 
    public interface SpaceCharFilter {
        public boolean isSpaceChar(int ch);
    }
}