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