Added reference to HackerRank Fundamental Mathematics Problem 'Best Divisor'.
Added reference to HackerRank Fundamental Mathematics Problem 'Best Divisor'.

shivkrthakur/HackerRankSolutions,shivkrthakur/HackerRankSolutions,shivkrthakur/HackerRankSolutions,shivkrthakur/HackerRankSolutions