RTLQF
      +----------
PTRQF | PRQQFQPTF
       -PTRQF
        =====
         RLTTQP
        -RTTLFU
         ======
          RFNQUT
         -RPTPQN
          ======
           QPFLQF
          -QPRLQR
           ======
             UTTU

base: 8
letters: FLNPQRTU
difficulty: easy
restrictions: no multiplication