public class NumberUtilities {
    public static String getRange(int stop) {
        StringBuilder range = new StringBuilder();

        for(int i=0; i<stop; i++){
            range.append(i);
        }

        return range.toString();
    }

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

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

        return range.toString();
    }

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

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

        return range.toString();
    }

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

        if (start % 2 == 0){
            for(int i=start; i<stop; i += 2){
                range.append(i);
            }
        } else {
            for(int i=start+1; i<stop; i += 2){
                range.append(i);
            }
        }

        return range.toString();
    }

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

        if (start % 2 == 0){
            for(int i=start+1; i<stop; i += 2){
                range.append(i);
            }
        } else {
            for(int i=start; i<stop; i += 2){
                range.append(i);
            }
        }

        return range.toString();
    }
    
    public static String getSquareNumbers(int start, int stop){
        StringBuilder range = new StringBuilder();

        for(int i=start; i<=stop; i ++){
            range.append(i*i);
        }

        return range.toString();
    }

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

        for(int i=start; i<=stop; i++){
            range.append((int)Math.pow(i, exponent));
        }

        return range.toString();
    }
}