subroutine sum(x, res)
implicit none
real, intent(in) :: x(:)
real, intent(out) :: res
integer :: i
!print *, "sum: size(x) = ", size(x)
res = 0.0
do i = 1, size(x)
res = res + x(i)
enddo
end subroutine sum
function fsum(x) result (res)
implicit none
real, intent(in) :: x(:)
real :: res
integer :: i
!print *, "fsum: size(x) = ", size(x)
res = 0.0
do i = 1, size(x)
res = res + x(i)
enddo
end function fsum