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