RNJY
    +-------
PTQ | QRHGRU
     -MRR
      ===
       XYG
      -XTN
       ===
        MHR
       -RWY
        ===
        PFQU
       -PFUJ
        ====
          UN

base: 15
letters: FGHJLMNPQRTUWXY
difficulty: hard
missing: L