????????
      +---------
PTJHU | JHXYYYHQ
       -PTJHU
        =====
        UURMNY
       - YPPRJ
        ======
         LPLFXH
        -LUYGRH
         ======
          ULGJWQ
         - YPPRJ
          ======
          ??????

base: 15
letters: FGHJLMNPQRTUWXY
difficulty: easy