Codeforces Round 232 (Div. 1)
E
On Iteration of One Well-Known Function
Codeforces
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原题
← D→
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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?

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

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Input

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The first line contains integer $*m*$ ($1 ≤ *m* ≤ 10^{5}$) — the number of distinct prime divisors in the canonical representaion of $*n*$.

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Each of the next $*m*$ lines contains a pair of space-separated integers $*p*_{*i*}, *a*_{*i*}$ ($2 ≤ *p*_{*i*} ≤ 10^{6}; 1 ≤ *a*_{*i*} ≤ 10^{17}$) — another prime divisor of number $*n*$ and its power in the canonical representation. The sum of all $*a*_{*i*}$ doesn't exceed $10^{17}$. Prime divisors in the input follow in the strictly increasing order.

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The last line contains integer $*k*$ ($1 ≤ *k* ≤ 10^{18}$).

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Output

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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.

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Each of the next $*w*$ lines must contain two space-separated integers $*q*_{*i*}, *b*_{*i*}$ $(*b*_{*i*} ≥ 1)$ — another prime divisor and its power in the canonical representaion of the result. Numbers $*q*_{*i*}$ must go in the strictly increasing order.

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Note

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You can read about canonical representation of a positive integer here: http://en.wikipedia.org/wiki/Fundamental_theorem_of_arithmetic.

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You can read about function $φ(*n*)$ here: http://en.wikipedia.org/wiki/Euler's_totient_function.

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样例

Input #1
1
7 1
1
Output #1
2
2 1
3 1
InputCopy OutputCopy
Input #2
1
7 1
2
Output #2
1
2 1
InputCopy OutputCopy
Input #3
1
2 100000000000000000
10000000000000000
Output #3
1
2 90000000000000000
InputCopy OutputCopy
题目信息
题号
396E
时间限制
1 s
内存限制
256 MB
标签
数学

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