Assignment:
The positive integers are classified into two types, A and B; a number is A if and only if it is the sum of two (distincts) A numbers, or the sum of two (distincts) B numbers.
a) Classify the numbers 1,2, 3 as A and B.
b) Prove that if n, n+1, n+2 are A numbers, then every integer >= n is an A number.
c) Find the smallest n so that every integer >= n is an A number.
Provide complete and step by step solution for the question and show calculations and use formulas.