There are N children in AtCoder Kindergarten. Mr. Evi will arrange the children in a line, then give 1 candy to the first child in the line, 2 candies to the second child, ..., N candies to the N-th child. How many candies will be necessary in total?
N = int(input())
answer = N * (N + 1) / 2
print(answer)
N = int(input())
answer = N * (N + 1) // 2
print(answer)