# subset 1 of (A..Z)
set_1 = (A, B, C, X, Y, Z)
# subset 2 of (a..z)
set_2 = (q, w, r, t, u)
# valid pairs
valid = ((A,q) = 1, (A,u) = 6, (A,k) => 3, (C,t) = 10, (Z,u) = 30)