program main

 implicit none

 integer                 :: n,m,i,j,ierr 
 integer,    allocatable :: f(:),v(:),g(:)
 real*8                  :: rtmp,itmp,sum_row,sumt
 real*8,     allocatable :: b(:,:),c(:)
 real*8,     allocatable :: d(:)
 complex(8), allocatable :: a(:,:)

 !1)
 do
  write(*,*) 'Insert n>0'
  read(*,*) n
  if (n.gt.0) exit
 enddo 

 allocate(a(n,n))
 allocate(b(n,n))
 allocate(c(n))
 allocate(d(n))
 allocate(f(n))

 open(10,file='inputA.dat',status='old',iostat=ierr,err=500)
 do i=1,n
    do j=1,n
       read(10,*) rtmp,itmp
       a(j,i)=dcmplx(rtmp,itmp)
    enddo
 enddo   
 close(10)

 !2)
 sumt=1.d0
 do i=1,n
    sum_row=0.d0
    do j=1,n
       sum_row=sum_row+abs(a(i,j)) 
    enddo
    sumt = sumt*sum_row 
 enddo

 write(*,*) 'The value is', sumt
 if (sumt.gt.0.d0.and.sumt.le.4.d0) then
    do i=1,n
       do j=1,n
          b(i,j)=dble(a(i,j))
       enddo
    enddo   
 elseif (sumt.gt.4.d0.and.sumt.le.8.d0) then
    do i=1,n
       do j=1,n
          b(i,j)=aimag(a(i,j))
       enddo
    enddo   
 elseif (sumt.gt.8.d0) then
    do i=1,n
       do j=1,n
          b(i,j)=abs(a(i,j))
       enddo
    enddo   
 endif        


 !3)
 do i=1,n
    d(i)=b(i,n-(i-1))
 enddo

 call prod(c,b,d,n) 

 call do_f(f,c,b,n)


 !4)
 do 
   write(*,*) 'Insert m>0'
   read(*,*) m
   if (m.gt.0) exit
 enddo

 call modify_f(m,n,f)


 !5)
 allocate(v(m))
 open(11,file='inputv.dat',status='old',iostat=ierr,err=500)
 do i=1,m
       read(11,*) v(i) 
 enddo
 close(11)

 allocate(g(m+n))

 do i=1,m
    g(i)=v(i)
 enddo   

 do i=1,n
    g(m+i)=f(i)
 enddo

 call sort(g,n,m)


 !6)
 open(20,file='a.dat')
 open(21,file='b.dat')
 do i=1,n
    do j=1,n
       write(20,205) i,j,dble(a(i,j)),aimag(a(i,j))
       write(21,200) i,j,b(i,j)
    enddo
 enddo   
 close(20)
 close(21)

 open(22,file='c.dat')
 open(23,file='g.dat')
 do i=1,n
    write(22,215) i, c(i)
 enddo 
 do i=1,n+m
    write(23,210) i, g(i)
 enddo
 close(22)
 close(23)

200 format(I4,I4,F12.6)
205 format(I4,I4,2(F12.6))
210 format(I4,I4)
215 format(I4,F12.6)

500 if (ierr.ne.0) then
       write(*,*) 'Error in opening the input file'
       stop
    endif

 deallocate(a)
 deallocate(b)
 deallocate(c)
 deallocate(d)
 deallocate(f)
 deallocate(g)
 deallocate(v)

 stop

end program main  


subroutine prod(c,b,d,n)

 implicit none

 integer, intent(in)  :: n
 real*8,  intent(in)  :: b(n,n),d(n)
 real*8,  intent(out) :: c(n)

 integer              :: i,j 

 c=0.d0
 do i=1,n
    do j=1,n
       c(i)=c(i)+b(i,j)*d(j)
    enddo
 enddo

 return
 
end subroutine prod        

subroutine do_f(f,c,b,n)

 implicit none

 integer,  intent(in)  :: n
 real*8,   intent(in)  :: c(n)
 real*8,   intent(in)  :: b(n,n)
 integer,  intent(out) :: f(n)

 integer               :: i
 real*8                :: tmp
 do i=1,n
    tmp=b(i,i)-c(i)
    f(i) = ceiling(tmp) 
 enddo

 return

end subroutine do_f 

subroutine modify_f(m,n,f)

 implicit none

 integer,  intent(in)    ::m,n
 integer,  intent(inout) :: f(n)

 integer                 :: i

 if (m.ge.n) then
    do i=1,n/2,2
       f(i)=f(i)+(m-n)
    enddo
    do i=2,n/2,2
       f(i)=f(i)+(n-m)
    enddo
 else
    do i=n/2+1,n
       f(i)=f(i)+(n+m)
    enddo
 endif        

 return 

end subroutine modify_f       


subroutine sort(g,n,m)

  implicit none      

  integer,         intent(in)    :: n,m
  integer,         intent(inout) :: g(n+m)

  integer                        :: i,j,tmp

  do i=1,n+m
     do j=2,n+m-(i-1)
        if (g(j-1).gt.g(j)) then
           tmp=g(j-1)
           g(j-1)=g(j)
           g(j)=tmp
        endif
     enddo
  enddo

  return

end subroutine sort