(;AW[pq]AW[qp]AW[qo]AW[oq]AB[qq]AB[pr]AB[rq]AW[or]AB[qs]AW[sr]C[Black to live]AP[goproblems]
(;B[rr];W[os]
(;B[ss]
(;W[rs]
(;B[sq];W[ps]
(;B[qr]C[RIGHT])
(;B[ss];W[qr]C[Ko - black can do better]))
(;B[rp];W[ps]C[Ko - black can do better]))
(;W[ps];B[qr]C[Black is alive.]))
(;B[sq];W[ps]C[Ko - black can do better])
(;B[ps];W[rs]C[Ko - black can do better.]))
(;B[rp];W[ro]
(;B[rr];W[os];B[ps];W[rs]C[Ko - black can do better])
(;B[sp];W[rr])
(;B[rs];W[rr])
(;B[ps];W[os];B[rr];W[rs]C[Ko - black can do better]))
(;B[rs];W[rr]))