(;AB[pq]AB[qp]AB[rq]AB[sq]AB[rp]AB[or]AB[nr]AW[oq]AW[op]AW[po]AW[qo]AW[ro]AW[pr]AW[qr]AW[so]AW[sp]AB[lq]C[do your best for saving marked stones!]TR[pq]TR[qp]TR[rp]TR[rq]TR[sq]AP[goproblems]
(;B[rr];W[rs]
(;B[ss];W[sr]C[];B[ps];W[pp];B[ss]C[ko and b takes first :-)RIGHT])
(;B[ps];W[pp];B[ss];W[sr]C[ko but b doesn't have any more his local ko threat at q1:(]))
(;B[rs];W[rr];B[sr];W[pp];B[ps];W[qq])
(;B[qq];W[rr])
(;B[qs];W[rr])
(;B[ps];W[rr]))