(;AB[qs]AB[rr]AB[rq]AW[rp]AW[ro]AW[rn]AW[qr]AW[qq]AB[qp]AB[pp]AB[pq]AW[pr]AW[or]AW[oq]AW[op]AB[qn]AB[rm]AB[ql]AB[rl]AB[pm]AB[pl]AW[ol]AW[ok]AW[om]AW[pj]AW[rj]AB[pn]AW[on]AW[no]AW[qi]C[This one is hell hard :)]AP[goproblems]
(;B[sr]
(;W[rs]
(;B[qo];W[so]
(;B[sq];W[sm]
(;B[ss]
(;W[ps]C[CHOICE];B[sl];W[rs];B[sn];W[sp]C[];B[rq]C[Good job mate.RIGHT])
(;W[sl]C[May seem like trick to someone, but it isn't :)];B[sk];W[ps];B[sn];W[sm];B[sl];W[rs];B[sn];W[sp];B[rq]C[RIGHT]))
(;B[sl];W[ps]TR[rq]TR[sq]TR[sr]TR[rr]C[2 step ko for white, but when he takes marked stones, there is no trick left for you.]LB[qs:1]LB[ss:2]LB[sp:3]))
(;B[ss];W[ps]))
(;B[sq];W[sp])
(;B[ss];W[sp]
(;B[qo];W[sq])
(;B[sn];W[sq]))
(;B[sn];W[so];B[ss];W[sq]C[Ko])
(;B[sp];W[so];B[ss];W[sq])))
(;B[sq];W[ps]
(;B[rs];W[sp])
(;B[sn];W[rs];B[sp];W[sr]))
(;B[sp];W[sr];B[sq];W[ps]
(;B[rs];W[so])
(;B[ss];W[rs];B[sn];W[sr]C[Ko]))
(;B[qo];W[sr];B[sq];W[ps];B[sp];W[rs]C[Ko])
(;B[sn];W[sr];B[sp];W[rs]C[Ko])
(;B[so];W[sr]
(;B[sp];W[rs]C[Ko])
(;B[sn];W[sq]))
(;B[sm];W[sr]
(;B[sp];W[rs])
(;B[sq];W[ps]
(;B[rs];W[sp])
(;B[sp];W[rs])))
(;B[ss];W[sq];B[sp];W[so];B[qo];W[ps];B[sm];W[rs]))