pk1,pk2,pk3,content
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-b
b,a,b,b-a-b
b,b,b,b-b-b
b,c,b,b-c-b
b,d,b,b-d-b
b,e,b,b-e-b
b,f,b,b-f-b
b,g,b,b-g-b
b,h,b,b-h-b
b,i,b,b-i-b
b,j,b,b-j-b
b,k,b,b-k-b
b,l,b,b-l-b
b,m,b,b-m-b