Again XOR problem

You may have solved a lot of problems related to XOR and we are sure that you liked them, so here is one more problem for you. You are given a binary string $S$ of length $N$. Let string $T$ be the result of taking the XOR of **all** substrings of size $K$ of $S$. You need to find the number of `1` bits in $T$. **Note**: - A substring is a continuous part of string which can be obtained by delet