#P3994. Probability One

Probability One

Description

Number guessing is a popular game between elementary-school kids. Teachers encourage pupils to play the game as it enhances their arithmetic skills, logical thinking, and following-up simple procedures. We think that, most probably, you too will master in few minutes. Here’s one example of how you too can play this game: Ask a friend to think of a number, let’s call it n0. Then:

    <li>Ask your friend to compute n1 = 3 * n0 and to tell you if n1 is even or odd.</li>

    <li>If n1 is even, ask your friend to compute n2 = n1/2. If, otherwise, n1 was odd then let your friend compute n2 = (n1 + 1)/2.</li>

    <li>Now ask your friend to calculate n3 = 3 * n2.</li>

    <li>Ask your friend to tell tell you the result of n4 = n3/9. (n4 is the quotient of the division operation. In computer lingo, ’/’ is the integer-division operator.)</li>

    <li>Now you can simply reveal the original number by calculating n0 = 2 * n4 if n1 was even, or n0 = 2 * n4 + 1 otherwise.</li>

    Here’s an example that you can follow: If n0 = 37, then n1 = 111 which is odd. Now we can calculate n2 = 56, n3 = 168, and n4 = 18, which is what your friend will tell you. Doing the calculation 2 * n4 + 1 = 37 reveals n0.

    Input

    Your program will be tested on one or more test cases. Each test case is made of a single positive number (0 < n0 < 1,000,000).

    The last line of the input file has a single zero (which is not part of the test cases.)

    Output

    For each test case, print the following line:

    k. B Q

    Where k is the test case number (starting at one,) B is either ’even’ or ’odd’ (without the quotes) depending on your friend’s answer in step 1. Q is your friend’s answer to step 4.

    37
    38
    0
    1. odd 18
    2. even 19

    Source

    anarc 2009