????????
      ----------
MWPFY ) FQFRFRTX
       -UEWTR
        =====
        MTFXMR
       -MLXFRQ
        ======
         MEMQLT
        -MTPEQE
         ======
           XTEWX
          -FEPYP
           =====
           ?????

base: 13
symbols: EFGLMPQRTUWXY
difficulty: medium
missing: G