First is a phone screen, ask me about a Dynamic Programming problem. Such as there is a list contain some numbers less than 10, such as 1, 2, 3, 4, 5.. but don't know how many. How can you find the biggest one. And when I finish, the man try to change the difficult level of this question such as if there are more than 100 number in this list, or if i define the number as a int, how can i do if the number bigger than the limit of int...seems he want to ask me until I cannot answer the question...