As known, 1720D1 - Xor-Subsequence (easy version) has an ambiguous descriptioin. I'm the one of those who got misled during the contest. However, the misunderstood problem is solutable. Let's have a look.

**It is the misunderstood version of the problem. The only difference is that in this version** $$$b_i$$$ do be the subsequence of $$$a$$$, where any $$$b_i$$$ is an element of $$$a$$$. Note that $$$a_i<200$$$ remains true.

**Hint 1**

**Hint 2**

**Hint 3**

**solution**

However, I had no idea how to solve the misunderstood D2. Could anyone help me?

As I promised in my previous comments, I made this blog.