check timing of ps2 solution w/ longer and longer text files.
move to front, move to back.

Rules for programming
1) const will be all capitals
2) the outermost var will be just before the begin end. 
   main.
3) all iterative constructs will to documented with
   loop invariants
4) there will be no assignment of records
5) there will be no use of packed arrays
6) there will be no use of provided string types
   except to open files.