Algorithm - a sequence of instructions for solving a problem.

Discrete variable - a variable that takes on only values that are separated from each other, for example: integers.

Divisor of an integer - an integer that divides a given  integer without a remainder.

Graph - a set of vertices that can be joined with edges.

The greatest common divisor of two integers,  gcd, - the largest positive integer that divides both integers.

The least common multiple of two integers, lcm, - the least integer that is divisible by  both integers.