Computer simulations often require random numbers.
One way to generate pseudo-random numbers is via a function of the form
seed(x+1) = [ seed(x) + STEP ] % MOD where
"%" is the modulus operator.
Such a function will generate pseudo-random numbers
(seed) between 0 and MOD-1. One problem with functions of this form is that
they will always generate the same pattern over and over. In order to minimize
this effect, selecting the STEP and MOD values carefully can result in a
uniform distribution of all values between (and including) 0 and MOD-1.
For example, if STEP=3 and MOD=5, the function will
generate the series of pseudo-random numbers 0, 3, 1, 4, 2 in a repeating
cycle. In this example, all of the numbers between and including 0 and MOD-1
will be generated every MOD iterations of the function. Note that by the
nature of the function to generate the same seed(x+1) every time seed(x) occurs
means that if a function will generate all the numbers between 0 and MOD-1, it
will generate pseudo-random numbers uniformly with every MOD iterations.
If STEP = 15 and MOD = 20, the function generates the
series 0, 15, 10, 5 (or any other repeating series if the initial seed is other
than 0). This is a poor selection of STEP and MOD because no initial seed will
generate all of the numbers from 0 and MOD-1.
Your program will determine if choices of STEP and MOD
will generate a uniform distribution of pseudo-random numbers.
Input
Each line of input will contain a pair of integers for
STEP and MOD in that order (1<=STEP,MOD<=100000).
Output
For each line of input, your program should print the
STEP value right-justified in columns 1 through 10, the MOD value
right-justified in columns 11 through 20 and either "Good Choice" or
"Bad Choice" left-justified starting in column 25. The "Good
Choice" message should be printed when the selection of STEP and MOD will
generate all the numbers between and including 0 and MOD-1 when MOD numbers are
generated. Otherwise, your program should print the message "Bad
Choice". After each output test set, your program should print exactly
one blank line.
Sample Input
3
5
15
20
63923
99999
Sample Output
3 5 Good Choice
15 20 Bad Choice
63923 99999 Good Choice