YRH
      +---------
TMMHN | XXCMXXTR
       -XFNLTF
        ======
         RYXNRT
        - TMMHN
         ======
          NYHLFR
         -LHXRTM
          ======
           TYXYX

base: 11
letters: CFHLMNRTUXY
difficulty: intermediate
restriction: no multiplication
missing: U