a1? a2? a1? a3?

b1? b2? b3? a4?

aa? bb? cc? dd?

a1? b1? c1? d1?

a1? b2? c3? d4?

this? is? really? weird?

a1? b3? c3? d4?

a1? b3? a1? d4?

a1? a1? a1? a1?

aa1? aa2? aa1? aa3?

aa1? aa3? aa1? aa3?

whatever1? whatever2? whatever3? whatever4?

whatever2? whatever3? whatever4? whatever5?