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