agonzalez0515

class StringCalculator
    def self.add(numbers_string)
        invalid_input?(numbers_string) ? "Invalid Input" : add_all_numbers(numbers_string)
    end

    def self.invalid_input?(input_string)
        input_string.include?('-') || input_string.include?('.')
    end

    def self.add_all_numbers(numbers)