Write the function second_negative
that takes a list of numbers and returns the position (index) of the second negative number inside the list. If there is no second negative number, the function should return -1
. Note that in Python, the position of elements inside a list starts from zero.
second_negative([1, 5, -3, 2, -10, -20]) -> 4
second_negative([-5, 1, 2, 8, 10, 10]) -> -1