n = int(eval(input()))

sum = 0

for num in range(1,n + 1):

    sum += num

print(sum)
n = int(eval(input()))

print((sum(list(range(1,n+1)))))
n = int(eval(input()))
sum = 0
for num in range(1, n + 1):
    sum += num
print(sum)

n = int(eval(input()))
print((sum(list(range(1, n + 1)))))

-sum = 0 -for num in range(1, n + 1): -    sum += num -print(sum) +print((sum(list(range(1, n + 1)))))