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