program rot
        character*1 in(52),out(52)
        integer i,j
        integer*2 length
        
        byte bin(52),bout(52)
        equivalence(bin,in)
        equivalence(bout,out)
        character*16384 test
        logical found

        do i=1,26
           bin(i)=ichar('A')-1 +i
           bin(i+26) = ichar('a') -1 +i
        end do
        do i=1,13
           bout(i)=ichar('N')-1 +i
           bout(i+13) = ichar('A')-1+i
           bout(i+26)=ichar('n')-1 +i
           bout(i+39)=ichar('a')-1+i
        end do
        read (5,'(a)')test
        do i=len(test),1,-1
          if (test(i:i) .ne. ' ') then
             length=i
             goto 101
          end if
        end do
101     continue ! :)
        do i=1,length
           found = .false.
           do j=1,52
                if (test(i:i) .eq. in(j)) then
                   write(6,'(a,$)')out(j)
                   found = .true.
                end if
           end do
           if (.not. found) write(6,'(a,$)')test(i:i)
        end do
        write(6,'(1x)')
        end