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?
number = int(input("人数を入力＞"))
print(int(1/2*number*(number+1)))
number = int(input())

print(int((number + 1)*number/2))