Fortran Need help with Jacobi relaxation method for Dirichlet boundary conditions

[Nikolas_Ex_Aguirre]

TL;DR Summary

I have a problem with this code that i made. every time that i run it, this shows an error (is the same in the image), and i don't know how to fix this. It's a jacobi relaxation method for a dirichlet boundary conditions.

program r_jacobi

  implicit none

!!!!Variables!!!

  real*8 V, V_1, V_2, Lx, Ly
  integer n ,i , j, k, nx, ny
  real*8, allocatable :: arrx(:), arry(:), phi(:,:,:)
  real*8 x, xi, xf, y, yi, yf, dx, dy

  real*8 d, q, bx, by

  V=1
  V_1=V
  V_2=-V

  Lx = 2
  Ly = 1
  nx = 200
  ny = nx/2

  n = 200
  k = 200
  allocate(arrx(nx))
  allocate(arry(ny))
  allocate(phi(n,nx,ny))!!!GRID!!!

  xi = 0
  xf = Lx
  dx = (xf-xi)/(nx-1)
  yi = 0
  yf = Ly
  dy = (yf-yi)/(ny-1)

  d = 2*(dx**(-1)+dy**(-1))  do j = 1,ny
     do i = 1,nx
        x = xi+(i-1)*dx
        arrx(i) = x
        y = yi+(j-1)*dy
        arry(j)=y
     end do
  end do

!!!BC!!!

  do j = 1,ny
     do i = 1,nx
        phi(1,i,j) = (V_1+V_2)/2
     end do
  end do
 
  do i = 1, nx/2
     phi(1,i,1) = V_1
     phi(1,i,ny) = V_1
  end do

  do i = nx/2 +1, nx
     phi(1,i,1) = V_2
     phi(1,i,ny) = V_2
  end do

  do j = 1, ny
     phi(1,1,j) = V_1
     phi(1,nx,j) = V_2
  end do
!!!jacobi!!! 
!delta_2^x = u^n_j+1_k - 2 u^n_j_k + u^n_j-1_k
!delta_2^y = u^n_j_k+1 - 2 u^n_j_k + u^n_j_k-1

!alpha^0_jk = -2(1/dx^2 + 1/dy^2)
!alpha^1_jk = alpha^2_jk = -1/dx^2
!alpha^3_jk = alpha^4_jk = -1/dy^2  do k = 1, n
     do j = 2, ny-1
        do i = 2, nx-1
           bx = phi(k,i+1,j) - 2*phi(k,i,j) + phi(k,i-1,j)
           by = phi(k,i,j+1) - 2*phi(k,i,j) + phi(k,i,j-1)
           q = -dx**(-2)*(phi(k,i,j))*bx - dy**(-2)*phi(k,i,j)*by
           phi(k+1,i,j)=d**(-1)(q+dx**(-1)*(phi(k,i+1,j)+phi(k,i-1,j))+dy**(-1)*(phi(k,i,j+1)&
                +phi(k,i,j-1)))
        end do
     end do
  end do 
end program r_jacobi

 

[Mark44]

phi(k+1,i,j)=d**(-1)(q+dx**(-1)*(phi(k,i+1,j)+phi(k,i-1,j))+dy**(-1)*(phi(k,i,j+1)& +phi(k,i,j-1)))

The error message says there is a problem with line 94, which I've copied above. It looks to me like you are missing '*" to the right of the assignment operator, and between d**(-1) and the stuff following it. In other words,
phi(k+1, i, j) = d**(-1) * (a + dx**(-1) * ...
There might be other errors as well.

Do yourself and anyone else who has to read your code by inserting some spaces. If this makes the line too long, break up the line into multiple assignment statements.