The first move is a stange-looking one — but it works!
(;AB[rq]AB[qr]AB[pq]AB[pp]AB[op]AB[np]AB[mp]AB[lq]AB[kq]AB[jq]AB[jr]AB[js]AB[nr]AW[pr]AW[or]AW[oq]AW[nq]AW[mq]AW[lr]AW[kr]AW[ns]C[Black to play]AP[goproblems]
(;B[mr];W[ms]C[];B[mr]C[Black sacrifices a stone with 1, then plays in at 1 after White 2 that makes miai of 'a' and 'b'. RIGHT]LB[mr:1]LB[ms:2]LB[ls:a]LB[ps:b]
(;W[ps]C[Black sacrifices a stone with 1, then plays in at 1 after White 2 that makes miai of 'a' and 'b'. RIGHT]LB[ls:a]LB[ps:b]LB[mr:1]LB[ms:2];B[ls]
(;W[nr]C[RIGHT];B[ks]C[RIGHT])
(;W[ks]C[RIGHT];B[ls]C[RIGHT]))
(;W[ks]C[Black sacrifices a stone with 1, then plays in at 1 after White 2 that makes miai of 'a' and 'b'. RIGHT]LB[ls:a]LB[ps:b]LB[mr:1]LB[ms:2];B[ls]C[RIGHT])
(;W[ls]C[Black sacrifices a stone with 1, then plays in at 1 after White 2 that makes miai of 'a' and 'b'. RIGHT]LB[ls:a]LB[ps:b]LB[mr:1]LB[ms:2];B[ps]C[RIGHT])
(;W[nr]C[Black sacrifices a stone with 1, then plays in at 1 after White 2 that makes miai of 'a' and 'b'. RIGHT]LB[ls:a]LB[ps:b]LB[mr:1]LB[ms:2];B[ks]C[RIGHT];W[ps]C[RIGHT];B[ls]C[RIGHT]))
(;B[ks];W[mr]
(;B[ps];W[ls])
(;B[ls];W[ps]))
(;B[ps];W[mr])
(;B[ms];W[mr]
(;B[ks];W[ls])
(;B[ps];W[os]))
(;B[ls]
(;W[mr]C[CHOICE]
(;B[ps];W[ks])
(;B[ks];W[ps])
(;B[ms];W[ks])
(;B[os];W[ps];B[ks];W[ms]))
(;W[ps];B[mr];W[ms];B[mr])))