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#F0653. Numbers

    ID: 659 传统题 2000ms 256MiB 尝试: 0 已通过: 0 难度: (无) 上传者: 标签>数论数学难度待定难度共享题库Codeforces英文题面题目来源题面语言

Numbers

题目描述

D. Numbers
time limit per test
3 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

One quite ordinary day Valera went to school (there's nowhere else he should go on a week day). In a maths lesson his favorite teacher Ms. Evans told students about divisors. Despite the fact that Valera loved math, he didn't find this particular topic interesting. Even more, it seemed so boring that he fell asleep in the middle of a lesson. And only a loud ringing of a school bell could interrupt his sweet dream.

Of course, the valuable material and the teacher's explanations were lost. However, Valera will one way or another have to do the homework. As he does not know the new material absolutely, he cannot do the job himself. That's why he asked you to help. You're his best friend after all, you just cannot refuse to help.

Valera's home task has only one problem, which, though formulated in a very simple way, has not a trivial solution. Its statement looks as follows: if we consider all positive integers in the interval [a;b] then it is required to count the amount of such numbers in this interval that their smallest divisor will be a certain integer k (you do not have to consider divisor equal to one). In other words, you should count the amount of such numbers from the interval [a;b], that are not divisible by any number between 2 and k-1 and yet are divisible by k.

Input

The first and only line contains three positive integers a, b, k (1≤ab≤2·109,2≤k≤2·109).

Output

Print on a single line the answer to the given problem.

Examples
Input
1 10 2
Output
5
Input
12 23 3
Output
2
Input
6 19 5
Output
0
Note

Comments to the samples from the statement:

In the first sample the answer is numbers 2,4,6,8,10.

In the second one − 15,21

In the third one there are no such numbers.


题目来源:fps-www.educg.net-codeforce-1-2833.xml.zip;FPS 共享题包,题包内第 66 题。保留原作者与原赛事署名。