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