(;SZ[4]AB[cb]AB[bc]AB[ad]AW[cc]AW[dd]AW[dc]AW[cd]AW[bb]AW[ab]AW[aa]AW[ba]C[FORCE]AP[goproblems]
(;B[ac]C[FORCE];W[bd])
(;B[bd]C[FORCE];W[ac])
(;B[ca]C[FORCE]
(;W[bd]C[FORCE]
(;B[ac]C[FORCE];W[bb])
(;B[da]C[FORCE]
(;W[ac])
(;W[db]))
(;B[db]C[RIGHT]))
(;W[da]C[FORCE]
(;B[ac]C[RIGHT])
(;B[bd]C[FORCE]
(;W[ac])
(;W[db]))
(;B[db]C[FORCE];W[da]))
(;W[db]C[FORCE]
(;B[ac]C[RIGHT])
(;B[bd]C[FORCE];W[ac])))
(;B[da])
(;B[db]C[FORCE]
(;W[ac]C[FORCE]
(;B[bd]C[FORCE];W[cc]C[FORCE]
(;B[ca]C[RIGHT])
(;B[da])
(;B[dc]C[FORCE];W[cd])
(;B[dd])
(;B[cd]C[FORCE];W[dd]))
(;B[ca]C[RIGHT])
(;B[da]C[FORCE]
(;W[bd])
(;W[ca])))
(;W[ca]C[FORCE]
(;B[ac]C[FORCE];W[bd])
(;B[bd]C[RIGHT]))
(;W[da]C[FORCE]
(;B[ac]C[FORCE]
(;W[bd])
(;W[ca]))
(;B[bd]C[RIGHT])
(;B[ca]C[FORCE];W[da]))))