private void Simplify(BigInteger num, BigInteger den)
        {
            BigInteger gcd = countGCD(num, den);
            numerator = numerator / gcd;
            denominator = denominator / gcd;
        }


        private BigInteger countGCD(BigInteger num, BigInteger den)
        {
            while(num != den)
            {
                if(num < den)
                {
                    den -= num;
                } else
                {
                    num -= den;
                }
            }

            return num;
        }