A11732 | Mahmoud and Ehab and yet another xor task

Ehab has an array $a$ of $n$ integers. He likes the [bitwise-xor operation](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) and he likes to bother Mahmoud so he came up with a problem. He gave Mahmoud $q$ queries. In each of them, he gave Mahmoud 2 integers $l$ and $x$ , and asked him to find the number of subsequences of the first $l$ elements of the array such that their bitwise-xor sum is $x$ . Can you help Mahmoud answer the queries?

A subsequence can contain elements that are not neighboring.

The first line contains integers $n$ and $q$ $(1<=n,q<=10^{5})$ , the number of elements in the array and the number of queries.

The next line contains $n$ integers $a_{1}$ , $a_{2}$ , $...$ , $a_{n}$ $(0<=a_{i}<2^{20})$ , the elements of the array.

The next $q$ lines, each contains integers $l$ and $x$ $(1<=l<=n$ , $0<=x<2^{20})$ , representing the queries.

For each query, output its answer modulo $10^{9}+7$ in a newline.