N = int(eval(input()))



ans = int(sum([j * (N//j)*(N//j+1)/2 for j in range(1,N+1)]))



print(ans)

N = int(eval(input()))



def gen():

  for j in range(1,N+1):

    yield j * (N//j)*(N//j+1)/2



ans = int(sum(gen()))



print(ans)

N = int(eval(input()))
ans = int(sum([j * (N // j) * (N // j + 1) / 2 for j in range(1, N + 1)]))
print(ans)

N = int(eval(input()))


def gen():
    for j in range(1, N + 1):
        yield j * (N // j) * (N // j + 1) / 2


ans = int(sum(gen()))
print(ans)

-ans = int(sum([j * (N // j) * (N // j + 1) / 2 for j in range(1, N + 1)])) + + +def gen(): +    for j in range(1, N + 1): +        yield j * (N // j) * (N // j + 1) / 2 + + +ans = int(sum(gen()))