import java.awt.*;
import java.io.*;
import java.math.*;
import java.util.*;
import static java.lang.Math.*;

public class BetaRound81_B implements Runnable {

    BufferedReader in;
    PrintWriter out;
    StringTokenizer tok = new StringTokenizer("");

    public static void main(String[] args) {
        new Thread(null, new BetaRound81_B(), "", 256 * (1L << 20)).start();
    }

    public void run() {
        try {
            long t1 = System.currentTimeMillis();
            if (System.getProperty("ONLINE_JUDGE") != null) {
                in = new BufferedReader(new InputStreamReader(System.in));
                out = new PrintWriter(System.out);
            } else {
                in = new BufferedReader(new FileReader("input.txt"));
                out = new PrintWriter("output.txt");
            }
            Locale.setDefault(Locale.US);
            solve();
            in.close();
            out.close();
            long t2 = System.currentTimeMillis();
            System.err.println("Time = " + (t2 - t1));
        } catch (Throwable t) {
            t.printStackTrace(System.err);
            System.exit(-1);
        }
    }

    String readString() throws IOException {
        while (!tok.hasMoreTokens()) {
            tok = new StringTokenizer(in.readLine());
        }
        return tok.nextToken();
    }

    int readInt() throws IOException {
        return Integer.parseInt(readString());
    }

    long readLong() throws IOException {
        return Long.parseLong(readString());
    }

    double readDouble() throws IOException {
        return Double.parseDouble(readString());
    }

    /** http://pastebin.com/j0xdUjDn */
    static class Utils {

        private Utils() {}

        public static void mergeSort(int[] a) {
            mergeSort(a, 0, a.length - 1);
        }

        private static final int MAGIC_VALUE = 50;

        private static void mergeSort(int[] a, int leftIndex, int rightIndex) {
            if (leftIndex < rightIndex) {
                if (rightIndex - leftIndex... What is the time complexity of the previous code?