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