CodeCraft-20 (Div. 2) |
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Finished |
It is Professor R's last class of his teaching career. Every time Professor R taught a class, he gave a special problem for the students to solve. You being his favourite student, put your heart into solving it one last time.
You are given two polynomials $$$f(x) = a_0 + a_1x + \dots + a_{n-1}x^{n-1}$$$ and $$$g(x) = b_0 + b_1x + \dots + b_{m-1}x^{m-1}$$$, with positive integral coefficients. It is guaranteed that the cumulative GCD of the coefficients is equal to $$$1$$$ for both the given polynomials. In other words, $$$gcd(a_0, a_1, \dots, a_{n-1}) = gcd(b_0, b_1, \dots, b_{m-1}) = 1$$$. Let $$$h(x) = f(x)\cdot g(x)$$$. Suppose that $$$h(x) = c_0 + c_1x + \dots + c_{n+m-2}x^{n+m-2}$$$.
You are also given a prime number $$$p$$$. Professor R challenges you to find any $$$t$$$ such that $$$c_t$$$ isn't divisible by $$$p$$$. He guarantees you that under these conditions such $$$t$$$ always exists. If there are several such $$$t$$$, output any of them.
As the input is quite large, please use fast input reading methods.
The first line of the input contains three integers, $$$n$$$, $$$m$$$ and $$$p$$$ ($$$1 \leq n, m \leq 10^6, 2 \leq p \leq 10^9$$$), — $$$n$$$ and $$$m$$$ are the number of terms in $$$f(x)$$$ and $$$g(x)$$$ respectively (one more than the degrees of the respective polynomials) and $$$p$$$ is the given prime number.
It is guaranteed that $$$p$$$ is prime.
The second line contains $$$n$$$ integers $$$a_0, a_1, \dots, a_{n-1}$$$ ($$$1 \leq a_{i} \leq 10^{9}$$$) — $$$a_i$$$ is the coefficient of $$$x^{i}$$$ in $$$f(x)$$$.
The third line contains $$$m$$$ integers $$$b_0, b_1, \dots, b_{m-1}$$$ ($$$1 \leq b_{i} \leq 10^{9}$$$) — $$$b_i$$$ is the coefficient of $$$x^{i}$$$ in $$$g(x)$$$.
Print a single integer $$$t$$$ ($$$0\le t \le n+m-2$$$) — the appropriate power of $$$x$$$ in $$$h(x)$$$ whose coefficient isn't divisible by the given prime $$$p$$$. If there are multiple powers of $$$x$$$ that satisfy the condition, print any.
3 2 2 1 1 2 2 1
1
2 2 999999937 2 1 3 1
2
In the first test case, $$$f(x)$$$ is $$$2x^2 + x + 1$$$ and $$$g(x)$$$ is $$$x + 2$$$, their product $$$h(x)$$$ being $$$2x^3 + 5x^2 + 3x + 2$$$, so the answer can be 1 or 2 as both 3 and 5 aren't divisible by 2.
In the second test case, $$$f(x)$$$ is $$$x + 2$$$ and $$$g(x)$$$ is $$$x + 3$$$, their product $$$h(x)$$$ being $$$x^2 + 5x + 6$$$, so the answer can be any of the powers as no coefficient is divisible by the given prime.
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