program main

 implicit none

 integer :: i,j,n,prod,m
 integer, allocatable :: a(:,:)
 real*8  :: h,integ,b1,b2,x,f,fmax,xmax

 !1)
 open(10,file='input')
 do 
   read(10,*) n
   if (n.gt.1) exit
 enddo  
 allocate(a(n,n))
 do i=1,n
    do j=1,n
       read(10,*) a(i,j)
    enddo   
 enddo   
 close(10)

 !2)
 call do_op(n,a,prod)

 !3)
 write(*,*) 'Number of points'
 read(*,*) m
 b1=-8.d0
 b2=8.d0
 h=(b2-b1)/dble(m)
 if (prod.gt.5.d0) then
    integ=f(b1)+f(b2)
    integ=0.5d0*integ

    do i=1,m-1
       x=b1+i*h
       integ=integ+f(x)
    enddo
    integ=integ*h
 else
   fmax=f(b1)
   write(*,*) 'primo',fmax
   do i=1,m
      x=b1+i*h
      if (f(x).gt.fmax) then
          fmax=f(x)
          xmax=x
          write(*,*) xmax,fmax
        endif   
   enddo
 endif  
 !4)
 write(*,*) 'The product is'
 write(*,101) prod

 if (prod.gt.5.d0) then
    write(*,*) 'Value of the integral'
    write(*,100) integ 
 else   
    write(*,*) 'Max value of f'
    write(*,100) fmax
    write(*,*) xmax
 endif

100 format(F10.3)
101 format(I5)

 deallocate(a)

 stop

 end program


 real*8 function f(x)
 
  implicit none

  real*8, intent(in) :: x 

  f = exp(-0.1d0*x**2)
  
  return

 end function


 subroutine do_op(n,a,res)

  implicit none

  integer, intent(in) :: n
  integer, intent(in) :: a(n,n) 
  integer, intent(out) :: res

  integer  :: itmp,i,j

  res=1

  do i=1,n
     do j=1,n
        itmp=i+j
        if (mod(itmp,2).ne.0) then
            res=res*a(i,j)
        endif
     enddo
  enddo

  return

  end subroutine