module adder
    implicit none
contains

    subroutine zadd(a, b, c, n)
        integer, intent(in) :: n
        double complex, intent(in) :: a(n), b(n)
        double complex, intent(out) :: c(n)
        integer :: j
        do j = 1, n
            c(j) = a(j) + b(j)
        end do
    end subroutine zadd

end module adder