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() )

sum = ( n + 1 ) * n * 0.5
print( sum )

n = int( input() )

print( int((n+1)*n*0.5) )