????????
      +---------
MHRWC | TWTLTMGH
       -THGRG
        =====
         WMGMM
        -MHRWC
         =====
         RMMCGG
        -RMHCMC
         ======
           MHRTH
          -MHRWC
           =====
           ?????

base: 10
letters: ACGHLMQRTW
missing: Q A
hints: L << Q, Q << A
difficulty: hard