pk1,pk2,pk3,content
b,a,a,b-a-a
b,a,b,b-a-b
b,a,c,b-a-c
b,a,d,b-a-d
b,a,e,b-a-e
b,a,f,b-a-f
b,a,g,b-a-g
b,a,h,b-a-h
b,a,i,b-a-i
b,a,j,b-a-j
b,a,k,b-a-k
b,a,l,b-a-l
b,a,m,b-a-m
b,a,n,b-a-n
b,a,o,b-a-o
b,a,p,b-a-p
b,a,q,b-a-q
b,a,r,b-a-r
b,a,s,b-a-s
b,a,t,b-a-t
b,a,u,b-a-u
b,a,v,b-a-v
b,a,w,b-a-w
b,a,x,b-a-x
b,a,y,b-a-y
b,a,z,b-a-z