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## Problem Description

Rar the Cat has obtained a LED strip filled with *N* individual LED lights and wants to code them to light up in a certain manner. He at first labels the lights from 1 to *N*, and then lights the LEDs based on the rules below.

Initially, all the LED lights are turned off. Then for each positive integer not greater than *N*, (1..N), Rar the Cat toggles all the LED lights which labels are multiples of that number. Toggling a LED light means that if the light was originally on, it will now be turned off. If it was originally off, it would be turned on, akin to flipping a light switch.

As an example: When *N* is 10, Rar the Cat does the following steps in order:

- Initially, all the LED lights are turned off. (Off: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
- Firstly, Rar the Cat toggles all the lights that are multiples of 1. (On: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
- Secondly, Rar the Cat toggles all the lights that are multiples of 2. (On: 1, 3, 5, 7, 9 | Off: 2, 4, 6, 8, 10)
- Thirdly, Rar the Cat toggles all the lights that are multiples of 3, thereby turning LED 3 and 9 off while turning LED 6 on. (On: 1, 5, 6, 7 | Off: 2, 3, 4, 8, 9, 10)
- Fourthly, Rar the Cat toggles all the lights that are multiples of 4, thereby turning LED 4 and 8 on. (On: 1, 4, 5, 6, 7, 8 | Off: 2, 3, 9, 10)
- Then, Rar the Cat toggles all the lights that are multiples of 5, thereby turning LED 5 off while turning LED 10 on. (On: 1, 4, 6, 7, 8, 10 | Off: 2, 3, 5, 9)
- Next, Rar the Cat toggles all the lights that are multiples of 6, thereby turning LED 6 off. (On: 1, 4, 7, 8, 10 | Off: 2, 3, 5, 6, 9, 10)
- Subsequently, Rar the Cat toggles all the lights that are multiples of 7, thereby turning LED 7 off. (On: 1, 4, 8, 10 | Off: 2, 3, 5, 6, 7, 9)
- After that, Rar the Cat toggles all the lights that are multiples of 8, thereby turning LED 8 off. (On: 1, 4, 10 | Off: 2, 3, 5, 6, 7, 8, 9)
- Finally, Rar the Cat toggles all the lights that are multiples of 9, thereby turning LED 9 on. (On: 1, 4, 9, 10 | Off: 2, 3, 5, 6, 7, 8)
- Lastly, Rar the Cat toggles all the lights that are multiples of 10, thereby turning LED 10 off. (On: 1, 4, 9 | Off: 2, 3, 5, 6, 7, 8, 10)

Rar the Cat would like to know how many LED lights are turned on in the LED strip at the end of the day.

## Input

Input consists of a single integer, *N*.

## Output

A single integer, denoting how many LED lights are switched on in the LED strip at the end of the day.

## Limits

Subtask 1 (9%): 0 < *N* ≤ 10

Subtask 2 (32%): 0 < *N* ≤ 1000

Subtask 3 (34%): 0 < *N* ≤ 1000000

Subtask 4 (25%): 0 < *N* ≤ 10^{18} (Please use long long to input)

Subtask 5 (0%): As per sample testcases.

## Sample Testcase 1

Input:

10

Output:

3

## Sample Testcase 2

**This testcase adheres to the limits of subtask 2 to 4 only.**

Input:

1000

Output:

31

## Sample Testcase 3

**This testcase adheres to the limits of subtask 3 and 4 only.**

Input:

1000000

Output:

1000

## Sample Testcase 4

**This testcase adheres to the limits of subtask 4 only.**

Input:

964785235727023492

Output:

982234817

### Tags

### Subtasks and Limits

Subtask | Score | #TC | Time | Memory | Scoring |
---|---|---|---|---|---|

1 | 9 | 10 | 1s | 64MB | Minimum |

2 | 32 | 10 | 1s | 64MB | Minimum |

3 | 34 | 10 | 1s | 64MB | Minimum |

4 | 25 | 20 | 1s | 64MB | Minimum |

5 | 0 | 4 | 1s | 64MB | Minimum |

### Judge Compile Command

g++-8 ans.cpp -o lights -Wall -Wshadow -static -O2 -lm -m64 -s -w -std=gnu++17 -fmax-errors=512