
ZOJ Problem Set  4123
Little Sub has just received an equation, which is shown below, as his birthday gift. $$a^x \equiv x^a (\text{mod } 2^p)$$ Given the value of $a$, please help Little Sub count the number of $x$ ($1 \le x \le 2^p$) which satisfies the equation. InputThere are multiple test cases. The first line of the input contains an integer $T$ (about 1000), indicating the number of test cases. For each test case: The first and only line contains two integers $a$ and $p$ ($1 \leq a \leq 10^9$, $1 \leq p \leq 30$). OutputFor each test case output one line containing one integer, indicating the answer. Sample Input2 6 12 8 16 Sample Output1023 16383 Author: CHEN, Jingbang Source: The 10th Shandong Provincial Collegiate Programming Contest 