can you solve my problem? I can`t figure out how fix it?!

codes:

program project

implicit none

doubleprecision :: l,w,dx,dy,tig,errorr,eps,beta,tb

doubleprecision,allocatable :: x(:),y(:),t(:,:),told(:,:),q2(:,

integer ::n,m,i,j,iteration

!open file

open(10,file=âinput.txtâ)

open(11,file=âoutput.pltâ)

open(12,file=âoutput.txtâ)

!reading input

read(10,*)
read(10,*) l

read(10,

*)*

read(10,) w

read(10,

read(10,

*)*

read(10,) n

read(10,

read(10,

*)*

read(10,) m

read(10,

read(10,

*)*

read(10,) tig

read(10,

read(10,

*)*

read(10,) tb

read(10,

read(10,

*)*

read(10,) eps

read(10,

!allocating

allocate (x(n),y(m),t(n,m),told(n,m),q2(n,m))

!grid generation

dx=l/(n-1)

dy=w/(m-1)

do i=1,n

x(i)=(i-1)*dx

end do

do j=1,m

y(j)=(j-1)*dy

end do

beta=dx/dy

!intial guess

```
t(:,:)=tig
```

!boundry condition

t(:,0)=tb

! function flux

do i=1,n

do j=1,m

q2(i,j)=(t(i-1,j)-2.0*t(i,j)+t(i+1,j))/(dx**2.0)
q2(0,j)=5*j+27

q2(i,0)=0.0

q2(n,j)=0.0

q2(i,m)=0.0

end do

end do

!solving problem

told(:,:)=t(:,

iteration=0

do

errorr=0.0

iteration=iteration+1

do i=2,n-1

do j=2,m-1

t(i,j) = (t(i-1,j)+told(i+1,j)+((beta**2.0) (t(i,j-1)+told(i,j+1))))/(2.0(1.0+(beta**2.0)))

errorr =max((abs(t(i,j)-told(i,j))),errorr)

q2(i,j)=(t(i-1,j)-2.0

*t(i,j)+t(i+1,j))/(dx**2.0)*

if (q2(0,j)=5j+27) exit

if (q2(0,j)=5

end do

end do

```
if(errorr<eps) exit
told(:,:)=t(:,:)
print *, iteration,errorr
end do
```

!writing results

write (11,*)âvariables=x,y,T zone i=â,m,âj=â,n
do i=1,n
do j=1,m
write (11,*) x(i),y(j),t(i,j)

write (12,*) x(i),y(j),t(i,j)

end do

end do

end program project