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