JYMW
      +---------
HMTRE | ETYPMTWL
       -YJMMH
        =====
         RHTJT
        -UJHTL
         =====
          PWHFW
         -ERULP
          =====
           TLYML
          -WFYUT
           =====
            LFPH

base: 13
letters: EFHJLMPRTUWXY
difficulty: medium
missing: X