????????
      +---------
TNRRY | YFFFGQQM
       -TNRRY
        =====
        RWRGJQ
       -RNFPRU
        ======
         RXGQNQ
        -RNFPRU
         ======
          QWQFNM
         -QTTFNM
          ======
          ??????

base: 13
letters: FGJMNPQRTUWXY
difficulty: medium