def f(n: int) -> int:
  if n == 0:
    return 1
  return n + g(n - 1)
def g(n: int) -> int:
  if n == 0:
    return 0
  return n - f(n - 1) // 2
for i in range(10):
  print(i, ': ', f(i), ' ', g(i), sep='')