????????
      ----------
RRHQF ) QNNNHYLF
       -QQYUW
        =====
         PFJRY
        -FFTHR
         =====
         WNYNQL
        -WXTXTN
         ======
          WFWJXF
         -WYMHGJ
          ======
          ??????

base: 15
symbols: FGHJLMNPQRTUWXY
difficulty: medium