/*
 * SumUp : Sum up (part of) the geometric series based on p/q.
 *     Ensure that q > p > 0.
 *     Compute (p/q)^0 + (p/q)^1 + (p/q)^2 + ...
 *
 *     Print number out with '?' in place of remaining digits
 *     we know have not converged yet.
 *
 * Parke Godfrey
 * 2009 October 27
 * (First implemented last year.)
*/

import java.io.PrintStream;
import java.util.Scanner;

public class SumUp
{
    public static void main(String[] args)
    {
        Scanner input = new Scanner(System.in);
        PrintStream output = System.out;

        final    int LOOP_LIM = 30;
        final double EPSILON  = 0.000001;

        // To collect the sum.  First term, 1, included.
        double sum = 1.;

        // Read in a numerator (> 0) from the user.
        // Loop until the user gets it right.
        // No comments first time through.
        boolean first = true;
        long numerator = 0;
        do
        {
            if (!first) {
                if (numerator <= 0)
                {
                    output.println(
                        "Numerator should be positive.");
                }
            }
            first = false;

            output.print("Enter the numerator: ");
            numerator = input.nextLong();
        } while (numerator <= 0);

        // Read in a denominator (> 0) from the user.
        // Also insist that denominator > numerator.
        // Loop until the user gets it right.
        first = true; // No corrections to user first time through.
        long denominator = 0;
        do
        {
            if (!first) {
                if (denominator <= 0)
                {
                    output.println(
                        "Denominator should be positive.");
                } else // if (denominator <= numerator)
                {
                    output.print("Denominator should larger ");
                    output.println("than numerator.");
                }
            }
            first = false;

            output.print("Enter the denominator: ");
            denominator = input.nextLong();
        } while ((denominator <= 0)
                    || (denominator <= numerator));

        double base = (double) numerator / denominator;
        double term = base;

        // Sum up while next term is larger than epsilon,
        // AND we are fewer than, or equal to, allowed #steps.
        int steps = LOOP_LIM;
        while ((EPSILON < term) && (steps > 0))
        {
            sum += term;
            term *= base;
            steps--;
        }

        // Figure out size of last term (not added).
        // String remS = (new Double(remD)).toString();
        String remS = String.format("%.5f", term);

        // String sumS = (new Double(sum)).toString();
        String sumS = String.format("%.5f", sum);

        // Confirm that doubles in Strings look like
        // we think they do.
        output.println("Remnant: " + remS);
        output.println("Sum:     " + sumS);
        assert(remS.matches("^\\d*\\.\\d+$"));
        assert(sumS.matches("^[0-9]*\\.[0-9]+$"));

        // Align the decimal points between them.
        int rDot = remS.indexOf(".");
        int sDot = sumS.indexOf(".");
        int r = 0;
        int s = sDot - rDot;

        // Read in the prefix of sumS that we are sure of
        // into the answer string.
        String answer = sumS.substring(0, s);

        // Shift all digits of sumS corresponding to '0' in remS
        // onto the answer string.
        while ((s < sumS.length())
                   && (r < remS.length())
                   && ((remS.charAt(r) == '0')
                           || (remS.charAt(r) == '.') ) )
        {
            answer += sumS.substring(s, s + 1);

            r++;
            s++;
        }
        // Write '?' for the remaining digits.
        for (; s < sumS.length(); s++) {
            if (sumS.charAt(s) == '.')
            {
                answer += ".";
            } else
            {
                answer += "?";
            }
        }

        // Print the resulting sum.
        output.println(answer);
    }
}