function nums0_100_text([n]) {
    let num = Number(n);
    let posDec = "";
    let posOne = "";
    let posTeen = "";
    let numWord = "";

    if (num >= 0 && num < 100) {
        let digitDEC = Math.floor(num / 10);
        let digitONE = num % 10;
        switch (digitONE) {
        case 0: posOne = "zero"; break;
        case 1: posOne = "one"; break;
        case 2: posOne = "two"; break;
        case 3: posOne = "three"; break;
        case 4: posOne = "four"; break;
        case 5: posOne = "five"; break;
        case 6: posOne = "six"; break;
        case 7: posOne = "seven"; break;
        case 8: posOne = "eight"; break;
        case 9: posOne = "nine"; break;
        default: break;
        }
        switch (digitDEC) {
        case 1:
        {
            switch (num) {
            case 10: posTeen = "ten"; break;
            case 11: posTeen = "eleven"; break;
            case 12: posTeen = "twelve"; break;
            case 13: posTeen = "thirteen"; break;
            case 14: posTeen = "fourteen"; break;
            case 15: posTeen = "fifteen"; break;
            case 16: posTeen = "sixteen"; break;
            case 17: posTeen = "seventeen"; break;
            case 18: posTeen = "eighteen"; break;
            case 19: posTeen = "nineteen"; break;
            default: break;
            }
        }; break;
        case 2: posDec = "twenty"; break;
        case 3: posDec = "thirty"; break;
        case 4: posDec = "forty"; break;
        case 5: posDec = "fifty"; break;
        case 6: posDec = "sixty"; break;
        case 7: posDec = "seventy"; break;
        case 8: posDec = "eighty"; break;
        case 9: posDec = "ninety"; break;
        default: break;
        }
        if (num == 0) {
            numWord = posOne;
        }
        else {
            if (digitDEC == 1) {
                numWord = posTeen;
            }
            else {
                if (num > 19) {
                    switch (digitONE) {
                    case 0: numWord = posDec; break;
                    default: numWord = posDec + " " + posOne; break;
                    }
                }
                else {
                    if (digitDEC == 0) {
                        numWord = posOne;
                    }
                }


            }
        }
        console.log(numWord);
    }
    else {
        if (num == 100) {
            console.log("one hundred");
        }
        else {
            console.log("invalid number");
        }
    }
}