THINK*NOT=ARMAMENTS ,

then try to restore the (not so clever) text below, coded by simple substitution:

7811$ 721$ , 7211$ 78 ; 6384 51$ 50 5298 7$ 705381 3078 .

rem1: You can go top down or bottom up.
rem2: Analytical approach preferred.

Actually, the bottom up approach was complicated by the 6384 that should have been 5384.  I guess that is why this problem was D4.

Posted by Steve Herman on 2017-11-30 16:04:59