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=input()
n=int(n)
print(n*(1+n)/2)
n=input()
n=int(n)
print(n*(1+n)//2)