The function can be implemented using a generator expression and the next() function. Given a list l of numbers. Iterate over the list and find the first even number from the list, i.e. el%2==0. Then iterate over the list to find the first odd number from the list, i.e. el%2!=0. Return a tuple containing the first even and odd number. If there is no even or odd number on the list then return -1.