# Sum Of Minimal Prime Divisors

Given an integer $N$ ($4 \le N \le 10^6$). Find the sum of minimal prime divisors of all **non-prime** integers between $2$ and $N$ inclusively.

## Input format
The input format contains one integer $N$ ($4 \le N \le 10^6$).

## Output format
Print one integer - the answer to the problem.

### Sample 1

#### Input

5

### Output

2

### Sample 2

#### Input

9

### Output

9