????????
      ----------
LRFQW ) XWFYUWLY
       -LRFQW
        =====
        PYFHNW
       -PYJRXG
        ======
          UFYRL
         -HGUGR
          =====
          LMMYYY
         -LMWQFQ
          ======
          ??????

base: 15
symbols: FGHJLMNPQRTUWXY
difficulty: hard
missing: T