CF396E.On Iteration of One Well-Known Function

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题目描述

Of course, many of you can calculate φ(n)φ(n) — the number of positive integers that are less than or equal to nn , that are coprime with nn . But what if we need to calculate φ(φ(...φ(n)))φ(φ(...φ(n))) , where function φφ is taken kk times and nn is given in the canonical decomposition into prime factors?

You are given nn and kk , calculate the value of φ(φ(...φ(n)))φ(φ(...φ(n))) . Print the result in the canonical decomposition into prime factors.

输入格式

The first line contains integer mm ( 1<=m<=1051<=m<=10^{5} ) — the number of distinct prime divisors in the canonical representaion of nn .

Each of the next mm lines contains a pair of space-separated integers pi,aip_{i},a_{i} ( 2<=pi<=106; 1<=ai<=10172<=p_{i}<=10^{6}; 1<=a_{i}<=10^{17} ) — another prime divisor of number nn and its power in the canonical representation. The sum of all aia_{i} doesn't exceed 101710^{17} . Prime divisors in the input follow in the strictly increasing order.

The last line contains integer kk ( 1<=k<=10181<=k<=10^{18} ).

输出格式

In the first line, print integer ww — the number of distinct prime divisors of number φ(φ(...φ(n)))φ(φ(...φ(n))) , where function φφ is taken kk times.

Each of the next ww lines must contain two space-separated integers qi,biq_{i},b_{i} (bi>=1)(b_{i}>=1) — another prime divisor and its power in the canonical representaion of the result. Numbers qiq_{i} 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)φ(n) here: http://en.wikipedia.org/wiki/Euler's_totient_function.

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