????????
      +---------
UUPJG | JYYYPLNG
       -JJLHW
        =====
         FGTUL
        -GGQPU
         =====
         WYLYJN
        -WMQMQY
         ======
          WGWTMG
         -WLXPRT
          ======
          ??????

base: 15
letters: FGHJLMNPQRTUWXY
difficulty: medium