CF396E.On Iteration of One Well-Known Function
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
Of course, many of you can calculate φ(n) — the number of positive integers that are less than or equal to n , that are coprime with n . But what if we need to calculate φ(φ(...φ(n))) , where function φ is taken k times and n is given in the canonical decomposition into prime factors?
You are given n and k , calculate the value of φ(φ(...φ(n))) . Print the result in the canonical decomposition into prime factors.
输入格式
The first line contains integer m ( 1<=m<=105 ) — the number of distinct prime divisors in the canonical representaion of n .
Each of the next m lines contains a pair of space-separated integers pi,ai ( 2<=pi<=106; 1<=ai<=1017 ) — another prime divisor of number n and its power in the canonical representation. The sum of all ai doesn't exceed 1017 . Prime divisors in the input follow in the strictly increasing order.
The last line contains integer k ( 1<=k<=1018 ).
输出格式
In the first line, print integer w — the number of distinct prime divisors of number φ(φ(...φ(n))) , where function φ is taken k times.
Each of the next w lines must contain two space-separated integers qi,bi (bi>=1) — another prime divisor and its power in the canonical representaion of the result. Numbers qi must go in the strictly increasing order.
输入输出样例
输入#1
1 7 1 1
输出#1
2 2 1 3 1
输入#2
1 7 1 2
输出#2
1 2 1
输入#3
1 2 100000000000000000 10000000000000000
输出#3
1 2 90000000000000000
说明/提示
You can read about canonical representation of a positive integer here: http://en.wikipedia.org/wiki/Fundamental_theorem_of_arithmetic.
You can read about function φ(n) here: http://en.wikipedia.org/wiki/Euler's_totient_function.