```    Program f07aj_a1w_fe

!     F07AJ_A1W_F Example Program Text
!     Mark 27 Release. NAG Copyright 2019.

!     .. Use Statements ..
Use iso_c_binding, Only: c_ptr
Assignment (=)
Use nag_library, Only: nag_wp, x04caf
!     .. Implicit None Statement ..
Implicit None
!     .. Parameters ..
Integer, Parameter               :: nin = 5, nout = 6
!     .. Local Scalars ..
Integer                          :: i, ifail, j, lwork, n
!     .. Local Arrays ..
Type (nagad_a1w_w_rtype), Allocatable :: a(:,:), a_in(:,:), work(:)
Real (Kind=nag_wp), Allocatable  :: ar(:,:), da(:,:)
Integer, Allocatable             :: ipiv(:)
!     .. Executable Statements ..
Write (nout,*) 'F07AJ_A1W_F Example Program Results'
!     Skip heading in data file

lwork = 64*n
Allocate (a(n,n),a_in(n,n),ipiv(n))
Allocate (ar(n,n),da(n,n),work(lwork))

!     Read A from data file
a_in = ar

!     Create AD configuration data object
ifail = 0

!     Register variables to differentiate w.r.t.

a = a_in

!     Factorize A
ifail = 0

Write (nout,*)
Flush (nout)

!     Compute inverse

!     Print solution
ar(1:n,1:n) = a(1:n,1:n)%value

!     ifail: behaviour on error exit
!            =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft
ifail = 0
Call x04caf('General',' ',n,n,ar,n,'Inverse',ifail)

Write (nout,*)
Write (nout,*) ' Derivatives calculated: First order adjoints'
Write (nout,*) ' Computational mode    : algorithmic'

Write (nout,*)
Write (nout,*) ' Derivatives of inverse diagonal w.r.t. diagonal of A'
Write (nout,*)
!     Setup evaluation of derivatives via adjoints
Do i = 1, n
ifail = 0

!       Get derivatives
Do j = 1, n