program zadatak_3
        real:: suma_x = 0, suma_y = 0
        !prethodno moze da se napise i kao real suma_x,suma_y
        !suma_x = 0
        !suma_y = 0
        dimension a(100,100)
        print *, "Uneti dimenzije matrice: "
        read *,n
        print *, "Uneti elemente matrice:"
        read(*,*) ((a(i,j),j=1,n),i=1,n)
        result = 0
        call fun(a,n,result)
        print *, result
        end


        subroutine fun(a,n, result)
         dimension a(100,100)
         suma_x = a(1,1) + a(1,n) + a(n,1) + a(n,n)
         suma_y = 0
         do i=1,n
           do j=1,n

              if(i .eq. 1 .or. i .eq. n) then
                     suma_y = suma_y + a(i,j)
              endif


           end do
        end do
        suma_y = suma_y - suma_x
        result = suma_x * suma_y
        !print *, suma_x
        !print *, suma_y
        return
        end