????????
      +---------
NPPXP | JFLUJRXG
       -NPPXP
        =====
        PJUGMR
       -PNNTHP
        ======
         PLMXWX
        -PYQGQY
         ======
          LGFMXG
         -LQMHJP
          ======
          ??????

base: 15
letters: FGHJLMNPQRTUWXY
difficulty: challenging
hints: N << H, R << F