** input 2 times
** memory layout: nact
n++[n-
 >>c,----------[
  ** convert character code to number
  >t++++++[-<c------>t]<c--
  ** add a x10 to c 
  <a[->c++++++++++<a]
  ** move back to a
  >c[-<a+>c]
 c,----------]
 ** move counter
 c<<n[->>c+<<n]
n>>cn ( slide )]
 
** add two numbers
<[-<<+>>]
 
** divmod loop
** memory layout: ndrq__
<<n[
 ** set 10 to d as a divide number
 >d++++++++++<n
 ** divmod
 n[->-[>+>>]>[+[-<+>]>+>>]<<<<<]
 ** clear d
 >d[-]
 ** increment r
 >r+
>qn]
 
** output loop
** memory layout: rt
<r[-
 ** convert a number to a character code
 >t++++++[-<r++++++++>t]
 <r.
r<<<r ( slide )]