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())

out=(N+1)*N/2
print(out)
N=int(input())

count=0
for i in range(N+1):
    count=count+i

print(count)
    