#P443. 【例78.1】忽明忽暗

【例78.1】忽明忽暗

Description

There are nn lights in the corridor, numbered from 11,22,33,...,nn, managed by the school's circuit control center. Initially, all lights are off. A hacker has infiltrated the school's circuit control center and wants to make the lights flicker by performing nn rounds of operations. In the ii-th round, the hacker toggles the state of all lights whose numbers are multiples of ii (turning on lights that are off and turning off lights that are on).
The hacker wants to know the sum of the numbers of all lights that are on after nn rounds of operations. Since the answer might be very large, please output the result modulo 109+710^9+7.

Input Format

A single integer nn, representing the number of lights. For 100% of the test cases, 1n10181≤n≤10^{18}.

Output Format

A single integer, representing the sum of the numbers of all lights that are on, modulo 109+710^9+7.

Sample

20
30