YJMX
      +---------
RRWJM | TFYTRTPJ
       -RRWJM
        =====
        FMXMTT
       -FHMXNQ
        ======
         QHLJRP
        -QLUTMJ
         ======
          YWYTXJ
         -YLHHRG
          ======
           QTPYJ

base: 15
letters: FGHJLMNPQRTUWXY
difficulty: medium