(;TR[es]TR[er]TR[eq]TR[cq]TR[dq]TR[bq]TR[aq]AB[ar]AB[as]AB[ds]C[FORCE]AP[goproblems] (;B[br]TR[es]TR[er]TR[dq]TR[eq]TR[cq]TR[bq]TR[aq]C[FORCE];W[cr]TR[es]TR[er]TR[eq]TR[dq]TR[cq]TR[bq]TR[aq]) (;B[cr]TR[es]TR[er]TR[eq]TR[dq]TR[cq]TR[bq]TR[aq]C[FORCE];W[bs]TR[es]TR[er]TR[eq]TR[dq]TR[cq]TR[bq]TR[aq]C[FORCE] (;B[br]TR[es]TR[er]TR[eq]TR[dq]TR[cq]TR[bq]TR[aq]C[RIGHT]) (;B[dr]TR[es]TR[er]TR[eq]TR[dq]TR[cq]TR[bq]TR[aq]AW[aq]AW[bq]AW[cq]AW[dq]AW[eq]AW[er]AW[es]C[FORCE];W[br]TR[es]TR[er]TR[eq]TR[dq]TR[cq]TR[bq]TR[aq]) (;B[cs]TR[es]TR[er]TR[eq]TR[dq]TR[cq]TR[bq]TR[aq]AW[aq]AW[bq]AW[cq]AW[dq]AW[eq]AW[er]AW[es]C[FORCE];W[br]TR[es]TR[er]TR[eq]TR[dq]TR[cq]TR[bq]TR[aq])) (;B[dr]TR[es]TR[er]TR[eq]TR[dq]TR[cq]TR[bq]TR[aq]C[FORCE] (;W[br]TR[es]TR[er]TR[eq]TR[dq]TR[cq]TR[bq]TR[aq]) (;W[cr]TR[es]TR[er]TR[eq]TR[dq]TR[cq]TR[bq]TR[aq]) (;W[cs]TR[es]TR[er]TR[eq]TR[dq]TR[cq]TR[bq]TR[aq]) (;W[bs]TR[es]TR[er]TR[eq]TR[dq]TR[cq]TR[bq]TR[aq])) (;B[cs]TR[es]TR[er]TR[eq]TR[dq]TR[cq]TR[bq]TR[aq]C[FORCE];W[br]TR[es]TR[er]TR[eq]TR[dq]TR[cq]TR[bq]TR[aq]C[even if black plays in B1, white wins by snapback.]) (;B[bs]TR[es]TR[er]TR[eq]TR[dq]TR[cq]TR[bq]TR[aq]C[FORCE];W[cr]TR[es]TR[er]TR[eq]TR[dq]TR[cq]TR[bq]TR[aq]C[even if black plays in C1, white can win by snapback.]))