Choose positive or negative integers for a and b, and a positive integer greater than 1 for 
c. For example, with the original choice, below, the linear congruence a x º b mod c has 
47 mutually incongruent solutions. By changing the values of a, b and c you'll obtain 
cases with a unique solution, no solution, or perhaps you'll produce the indeterminate
equation 0 x º 0 mod c. The check is provided to signal that the size limits on a, b and c
have been exceeded.