// We used these strings and constants in our say.cpp solution.
// They turned out to be quite useful, and made our solution more readable.
// You may use them too if you want, but it is not mandatory.

    const char *numName[] = { "", "one", "two", "three", "four",
        "five", "six", "seven", "eight", "nine", "ten", "eleven",
        "twelve", "thirteen", "fourteen", "fifteen", "sixteen",
        "seventeen", "eighteen", "nineteen"};

    const char *tensName[] = { "", "", "twenty", "thirty", "forty",
        "fifty", "sixty", "seventy", "eighty", "ninety"};

    const int TEN = 10, TWENTY = 20, HUNDRED = 100, THOUSAND = 1000,
           MILLION = 1000000, BILLION = 1000000000;