Hello 2019
D
Makoto and a Blackboard
Codeforces
2200
原题
← CE →
翻译中…

Makoto has a big blackboard with a positive integer $n$ written on it. He will perform the following action exactly $k$ times:

翻译中…

Suppose the number currently written on the blackboard is $v$. He will randomly pick one of the divisors of $v$ (possibly $1$ and $v$) and replace $v$ with this divisor. As Makoto uses his famous random number generator (RNG) and as he always uses $58$ as his generator seed, each divisor is guaranteed to be chosen with equal probability.

翻译中…

He now wonders what is the expected value of the number written on the blackboard after $k$ steps.

翻译中…

It can be shown that this value can be represented as $\frac{P}{Q}$ where $P$ and $Q$ are coprime integers and $Q \not\equiv 0 \pmod{10^9+7}$. Print the value of $P \cdot Q^{-1}$ modulo $10^9+7$.

翻译中…

Input

翻译中…

The only line of the input contains two integers $n$ and $k$ ($1 \leq n \leq 10^{15}$, $1 \leq k \leq 10^4$).

翻译中…

Output

翻译中…

Print a single integer — the expected value of the number on the blackboard after $k$ steps as $P \cdot Q^{-1} \pmod{10^9+7}$ for $P$, $Q$ defined above.

翻译中…

Note

翻译中…

In the first example, after one step, the number written on the blackboard is $1$, $2$, $3$ or $6$ — each occurring with equal probability. Hence, the answer is $\frac{1+2+3+6}{4}=3$.

翻译中…

In the second example, the answer is equal to $1 \cdot \frac{9}{16}+2 \cdot \frac{3}{16}+3 \cdot \frac{3}{16}+6 \cdot \frac{1}{16}=\frac{15}{8}$.

翻译中…

样例

Input #1
6 1
Output #1
3
InputCopy OutputCopy
Input #2
6 2
Output #2
875000008
InputCopy OutputCopy
Input #3
60 5
Output #3
237178099
InputCopy OutputCopy
题目信息
题号
1097D
所属比赛
时间限制
2 s
内存限制
256 MB
标签
动态规划
数学
数论
概率论

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。