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())

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