a x1 x1 a b a x1 a x1 b a a b x1 a a a a b b b x1 a a a a x1 b x1 2.2 b a a b x1 a a a b b b x1 b a a b x1 b b x1 a a a a x1 b x1 b a a b x1 b b b x1 b a a b x1 a a b b b x1 b a a b x1 a a a a b b b x1 b a a b x1 a b b b x1 true b a a b x1 a b b b x1 b a a b x1 a a a a b b b x1 b a a b x1 a a b b b x1 b a a b x1 b b x1 b a a b x1 b b b x1 a a a a x1 b x1 b a a b x1 a a a b b b x1 true Failed! NaTT certifiable-1.6