THXW
      ----------
 WXWW ) THYNAUHA
       -UWQWH
        =====
         HXNTU
        -QWUWT
         =====
          XXTWH
         -HWNWU
          =====
           WUAYA
          -XWAWN
           =====
            UWYW

base: 10
symbols: ACHNQTUWXY
difficulty: intermediate
missing: C