Codeforces Round 641 (Div. 2)
A
Orac and Factors
Codeforces
900
原题
←B →
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Orac is studying number theory, and he is interested in the properties of divisors.

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For two positive integers $a$ and $b$, $a$ is a divisor of $b$ if and only if there exists an integer $c$, such that $a\cdot c=b$.

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For $n \ge 2$, we will denote as $f(n)$ the smallest positive divisor of $n$, except $1$.

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For example, $f(7)=7,f(10)=2,f(35)=5$.

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For the fixed integer $n$, Orac decided to add $f(n)$ to $n$.

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For example, if he had an integer $n=5$, the new value of $n$ will be equal to $10$. And if he had an integer $n=6$, $n$ will be changed to $8$.

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Orac loved it so much, so he decided to repeat this operation several times.

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Now, for two positive integers $n$ and $k$, Orac asked you to add $f(n)$ to $n$ exactly $k$ times (note that $n$ will change after each operation, so $f(n)$ may change too) and tell him the final value of $n$.

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For example, if Orac gives you $n=5$ and $k=2$, at first you should add $f(5)=5$ to $n=5$, so your new value of $n$ will be equal to $n=10$, after that, you should add $f(10)=2$ to $10$, so your new (and the final!) value of $n$ will be equal to $12$.

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Orac may ask you these queries many times.

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Input

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The first line of the input is a single integer $t\ (1\le t\le 100)$: the number of times that Orac will ask you.

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Each of the next $t$ lines contains two positive integers $n,k\ (2\le n\le 10^6, 1\le k\le 10^9)$, corresponding to a query by Orac.

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It is guaranteed that the total sum of $n$ is at most $10^6$.

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Output

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Print $t$ lines, the $i$-th of them should contain the final value of $n$ in the $i$-th query by Orac.

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Note

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In the first query, $n=5$ and $k=1$. The divisors of $5$ are $1$ and $5$, the smallest one except $1$ is $5$. Therefore, the only operation adds $f(5)=5$ to $5$, and the result is $10$.

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In the second query, $n=8$ and $k=2$. The divisors of $8$ are $1,2,4,8$, where the smallest one except $1$ is $2$, then after one operation $8$ turns into $8+(f(8)=2)=10$. The divisors of $10$ are $1,2,5,10$, where the smallest one except $1$ is $2$, therefore the answer is $10+(f(10)=2)=12$.

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In the third query, $n$ is changed as follows: $3 \to 6 \to 8 \to 10 \to 12$.

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样例

Input #1
3
5 1
8 2
3 4
Output #1
10
12
12
InputCopy OutputCopy
题目信息
题号
1350A
时间限制
2 s
内存限制
256 MB
标签
数学

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。