Serval loves playing music games. He meets a problem when playing music games, and he leaves it for you to solve.
You are given $n$ positive integers $s_1 \lt s_2 \lt \ldots \lt s_n$. $f(x)$ is defined as the number of $i$ ($1\leq i\leq n$) that exist non-negative integers $p_i, q_i$ such that:
$$s_i=p_i\left\lfloor{s_n\over x}\right\rfloor + q_i\left\lceil{s_n\over x}\right\rceil$$
Find out $\sum_{x=1}^{s_n} x\cdot f(x)$ modulo $998\,244\,353$.
As a reminder, $\lfloor x\rfloor$ denotes the maximal integer that is no greater than $x$, and $\lceil x\rceil$ denotes the minimal integer that is no less than $x$.
Input
Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1\leq t\leq 10^4$). The description of the test cases follows.
The first line of each test cases contains a single integer $n$ ($1\leq n\leq 10^6$).
The second line of each test case contains $n$ positive integers $s_1,s_2,\ldots,s_n$ ($1\leq s_1 \lt s_2 \lt \ldots \lt s_n \leq 10^7$).
It is guaranteed that the sum of $n$ over all test cases does not exceed $10^6$, and the sum of $s_n$ does not exceed $10^7$.
Output
For each test case, print a single integer in a single line — the sum of $x\cdot f(x)$ over all possible $x$ modulo $998\,244\,353$.
Note
For the first test case, $s_n=4$, $f(x)$ are calculated as followings:
$f(1)=1$$\left\lfloor s_n\over 1\right\rfloor=4$,$\left\lceil s_n\over 1\right\rceil=4$.- It can be shown that such
$p_1,p_2$and$q_1,q_2$that satisfy the conditions don't exist. - Let
$p_3=1$and$q_3=0$, then$s_3 = p_3\cdot\left\lfloor s_n\over 1\right\rfloor + q_3\cdot\left\lceil s_n\over 1\right\rceil = 1\cdot 4 + 0\cdot 4 = 4$.
- It can be shown that such
$f(2)=2$$\left\lfloor s_n\over 2\right\rfloor=2$,$\left\lceil s_n\over 2\right\rceil=2$.- It can be shown that such
$p_1$and$q_1$that satisfy the conditions don't exist. - Let
$p_2=1$and$q_2=0$, then$s_2 = p_2\cdot\left\lfloor s_n\over 2\right\rfloor + q_2\cdot\left\lceil s_n\over 2\right\rceil = 1\cdot 2 + 0\cdot 2 = 2$. - Let
$p_3=0$and$q_3=2$, then$s_3 = p_3\cdot\left\lfloor s_n\over 2\right\rfloor + q_3\cdot\left\lceil s_n\over 2\right\rceil = 0\cdot 2 + 2\cdot 2 = 4$.
- It can be shown that such
$f(3)=3$$\left\lfloor s_n\over 3\right\rfloor=1$,$\left\lceil s_n\over 3\right\rceil=2$.- Let
$p_1=1$and$q_1=0$, then$s_1 = p_1\cdot\left\lfloor s_n\over 3\right\rfloor + q_1\cdot\left\lceil s_n\over 3\right\rceil = 1\cdot 1 + 0\cdot 2 = 1$. - Let
$p_2=0$and$q_2=1$, then$s_2 = p_2\cdot\left\lfloor s_n\over 3\right\rfloor + q_2\cdot\left\lceil s_n\over 3\right\rceil = 0\cdot 1 + 1\cdot 2 = 2$. - Let
$p_3=0$and$q_3=2$, then$s_3 = p_3\cdot\left\lfloor s_n\over 3\right\rfloor + q_3\cdot\left\lceil s_n\over 3\right\rceil = 0\cdot 1 + 2\cdot 2 = 4$.
- Let
$f(4)=3$$\left\lfloor s_n\over 4\right\rfloor=1$,$\left\lceil s_n\over 4\right\rceil=1$.- Let
$p_1=1$and$q_1=0$, then$s_1 = p_1\cdot\left\lfloor s_n\over 4\right\rfloor + q_1\cdot\left\lceil s_n\over 4\right\rceil = 1\cdot 1 + 0\cdot 1 = 1$. - Let
$p_2=1$and$q_2=1$, then$s_2 = p_2\cdot\left\lfloor s_n\over 4\right\rfloor + q_2\cdot\left\lceil s_n\over 4\right\rceil = 1\cdot 1 + 1\cdot 1 = 2$. - Let
$p_3=2$and$q_3=2$, then$s_3 = p_3\cdot\left\lfloor s_n\over 4\right\rfloor + q_3\cdot\left\lceil s_n\over 4\right\rceil = 2\cdot 1 + 2\cdot 1 = 4$.
- Let
Therefore, the answer is $\sum_{x=1}^4 x\cdot f(x) = 1\cdot 1 + 2\cdot 2 + 3\cdot 3 + 4\cdot 3 = 26$.
For the second test case:
$f(1)=f(2)=f(3)=1$$f(4)=3$$f(5)=f(6)=f(7)=f(8)=f(9)=4$
For example, when $x=3$ we have $f(3)=1$ because there exist $p_4$ and $q_4$:
$$9 = 1 \cdot\left\lfloor{9\over 3}\right\rfloor + 2 \cdot\left\lceil{9\over 3}\right\rceil$$
It can be shown that it is impossible to find $p_1,p_2,p_3$ and $q_1,q_2,q_3$ that satisfy the conditions.
When $x=5$ we have $f(5)=4$ because there exist $p_i$ and $q_i$ as followings:
$$1 = 1 \cdot\left\lfloor{9\over 5}\right\rfloor + 0 \cdot\left\lceil{9\over 5}\right\rceil$$ $$2 = 0 \cdot\left\lfloor{9\over 5}\right\rfloor + 1 \cdot\left\lceil{9\over 5}\right\rceil$$ $$7 = 3 \cdot\left\lfloor{9\over 5}\right\rfloor + 2 \cdot\left\lceil{9\over 5}\right\rceil$$ $$9 = 3 \cdot\left\lfloor{9\over 5}\right\rfloor + 3 \cdot\left\lceil{9\over 5}\right\rceil$$
Therefore, the answer is $\sum_{x=1}^9 x\cdot f(x) = 158$.
样例
4
3
1 2 4
4
1 2 7 9
4
344208 591000 4779956 5403429
5
1633 1661 1741 2134 2221
26
158
758737625
12334970
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