Problem Statement
Given an integer N, find the sum of all primes < N.
Input Format
The only line of the input file contains a positive integer N.

Output Format
Output the sum of all primes < N.

Constraints
1 ≤ N ≤ 4000000
You are guaranteed that the answer will fit in a 64-bit integer.

SAMPLE INPUT
1000

SAMPLE OUTPUT
76127

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