CF776E.The Holmes Children

普及/提高-

通过率:0%

AC君温馨提醒

该题目为【codeforces】题库的题目,您提交的代码将被提交至codeforces进行远程评测,并由ACGO抓取测评结果后进行展示。由于远程测评的测评机由其他平台提供,我们无法保证该服务的稳定性,若提交后无反应,请等待一段时间后再进行重试。

题目描述

The Holmes children are fighting over who amongst them is the cleverest.

Mycroft asked Sherlock and Eurus to find value of f(n)f(n) , where f(1)=1f(1)=1 and for n>=2n>=2 , f(n)f(n) is the number of distinct ordered positive integer pairs (x,y)(x,y) that satisfy x+y=nx+y=n and gcd(x,y)=1gcd(x,y)=1 . The integer gcd(a,b)gcd(a,b) is the greatest common divisor of aa and bb .

Sherlock said that solving this was child's play and asked Mycroft to instead get the value of . Summation is done over all positive integers dd that divide nn .

Eurus was quietly observing all this and finally came up with her problem to astonish both Sherlock and Mycroft.

She defined a kk -composite function Fk(n)F_{k}(n) recursively as follows:

She wants them to tell the value of Fk(n)F_{k}(n) modulo 10000000071000000007 .

输入格式

A single line of input contains two space separated integers nn ( 1<=n<=10121<=n<=10^{12} ) and kk ( 1<=k<=10121<=k<=10^{12} ) indicating that Eurus asks Sherlock and Mycroft to find the value of Fk(n)F_{k}(n) modulo 10000000071000000007 .

输出格式

Output a single integer — the value of Fk(n)F_{k}(n) modulo 10000000071000000007 .

输入输出样例

  • 输入#1

    7 1
    

    输出#1

    6
  • 输入#2

    10 2
    

    输出#2

    4

说明/提示

In the first case, there are 66 distinct ordered pairs (1,6)(1,6) , (2,5)(2,5) , (3,4)(3,4) , (4,3)(4,3) , (5,2)(5,2) and (6,1)(6,1) satisfying x+y=7x+y=7 and gcd(x,y)=1gcd(x,y)=1 . Hence, f(7)=6f(7)=6 . So, F1(7)=f(g(7))=f(f(7)+f(1))=f(6+1)=f(7)=6F_{1}(7)=f(g(7))=f(f(7)+f(1))=f(6+1)=f(7)=6 .

首页