public class NumberUtilities {
    public static String getRange(int start) {
        StringBuilder length = new StringBuilder();

        for(int i = 0; i < start ; i++){

            length.append(i);
        }

        return length.toString();

    }

    public static String getRange(int start, int stop) {
        StringBuilder length = new StringBuilder();

        for (int i = start;  i < stop; i++){
            length.append(i) ; 

        }
        return length.toString();

    }

    public static String getRange(int start, int stop, int step) {
        StringBuilder length = new StringBuilder();

        for (int i = start; i < stop; i += step){
            length.append(i);
        }
        return length.toString();

    }

    public static String getEvenNumbers(int start, int stop) {
        StringBuilder length = new StringBuilder();

        for (int i = start ; i < stop; i +=2){
            if (start %2 == 0){
                length.append(i);

            } else{
                length.append(i + 1);
            }

        }
        return length.toString();
    }

    public static String getOddNumbers(int start, int stop) {
        StringBuilder length = new StringBuilder();

        for (int i = start; i < stop; i +=2){
            if (start %2 == 1){
                length.append(i);

            }else{
                length.append(i + 1);

            }

        }
        return length.toString();
    }

    public static String getExponentiations(int start, int stop, int exponent) {
        StringBuilder length = new StringBuilder();

        for (int i = start; i <= stop; i++){

            length.append((int) Math.pow(i, exponent));

        }
        
        return length.toString();
    }
}