def oddSum(L: list[int], sum: int = 0) -> int:
    if len(L) == 0:
        return sum
    val = L[0]
    rest = L[1:]
    if val % 2 == 1:
        sum += val
    return oddSum(rest, sum)

def testOddSum():
    print('Testing oddSum()...', end='')
    assert(oddSum([]) == 0)
    assert(oddSum([1]) == 1)
    assert(oddSum([2]) == 0)
    assert(oddSum([1,2,3,4,5,4,3]) == 12)   # 1+3+5+3
    assert(oddSum([1,2,3,4,5,4,3,2]) == 12) # 1+3+5+3
    assert(oddSum([2,4,6,8,10,12,14]) == 0)
    assert(oddSum([1,1,1,1,1]) == 5) # 1+1+1+1+1
    print('Passed!')

def main():
    testOddSum()

main()