Black to play, and get the best result --- which is either a ko or seki.
(;SZ[19]DT[2022-09-28]AB[sr][rq][rp][ro][qo][po][pp][oq][nq][or][ns][ps][sq]AW[pr][pq][qq][rr][rs][op][oo][pn][qn][rn][so][om][sn]LB[sn:2][sq:1]C[Black to play, and get the best result --- which is either a ko or seki.](;B[qp];W[qr](;B[os];W[sp]C[Black loses all their stones.])(;B[ss];W[sp]C[Black loses all their stones.])(;B[qs];W[os]C[Black loses all their stones.]))(;B[qs];W[sp](;B[qp];W[ss]C[Black loses all their stones.])(;B[qr];W[os];B[ps];W[ss]C[Black loses all their stones.])(;B[os];W[qr]C[RIGHT This is a seki.]))(;B[qr];W[qs]LB[nn:Tenuki]C[There are a few options for black here. For a tenuki, play O6 (marked 'tenuki').](;B[nn]C[FORCE];W[os]C[RIGHT This is a ko.])(;B[qp]C[FORCE];W[os]C[RIGHT
This is a ko.])(;B[os]C[FORCE];W[sp]C[RIGHT
This is a seki.])(;B[ss];W[os]C[This is a ko.]))(;B[ss];W[sp]C[Black loses all their stones.])(;B[os];W[qr];B[qs];W[sp]C[RIGHT This is a seki.])(;B[sp];W[ss]C[Black loses all their stones.]))