private int getNumber(int[] number, int start, int end){
        int total = 0;
        for(int i = start; i <= end; i++){
            total *= 10;
            total += number[i];
        }
        return total;
    }
Number such that 11 + 11 = 22, 11 +22 = 33, 22 +33 = 55
so 1111223355 is aggregate number
src/com/interview/number/AggregateNumber.java