program sort3
	implicit none
        integer, parameter :: maxsize = 10
        real, dimension(maxsize) :: a
        logical :: exceed = .false.
        character(len=20) :: filename
        integer :: i
        integer :: nvals = 0
        integer :: status
        real :: temp

        write(*, 1000)
1000    format (1x, 'Enter the name of the file: ')
        read (*, '(A20)') filename
        open (unit = 9, file = filename, status='old', action='read', &
                iostat=status)
        fileopen: if (status==0) then
            do
                read(9, *, iostat=status) temp
                if (status /= 0) exit
                nvals = nvals+1
                size: if (nvals <= maxsize) then
                    a(nvals) = temp
                else
                    exceed = .true.
                end if size
            end do

            toobig: if (exceed) then
                write(*,1020) nvals, maxsize
1020            format('Max array size exceeded: ', I6, '>', I6)
            else toobig
                call sort(a, nvals)
                write(*, '(A)a') 'The sorted data:'
                write(*, 1040) (a(i),i=1, nvals)
1040            format (4x, f10.4)
            end if toobig
        else fileopen
            write(*,1050) status
1050        format(1x, 'File open failed-status = ', I6)
        end if fileopen
        end program

        subroutine sort(arr, n)
        implicit none
        integer, intent(in) :: n
        real, dimension(n), intent(inout) :: arr

        integer :: i
        integer :: iptr
        integer :: j
        real :: temp
       
        outer: do i = 1, n -1
            iptr = i
            inner: do j = i+1, n
                minval: if (arr(j) < arr(iptr)) then
                    iptr = j
                end if minval
            end do inner
            swap: if( i/= iptr) then
                temp = arr(i)
                arr(i) = arr(iptr)
                arr(iptr) = temp
            end if swap
        end do outer

        end subroutine sort