input: Write a function to sum all odd numbers up to a given number recursively.
  assert sum_odd_recurse(4) == 4
  assert sum_odd_recurse(10) == 25
  assert sum_odd_recurse(7) == 16
output: def sum_odd_recurse(n):
      if n <= 0:
          return 0
      if n % 2 == 0:
          return sum_odd_recurse(n - 1)
      else:
          return n + sum_odd_recurse(n - 2)