AcWing 2456. Notepad

Title Description
Initially, there was only one character on a notepad A.
You can do two things with this notebook at a time ：
Copy All ( Copy all ) :
You can copy all the characters in this Notepad ( Partial duplication is not allowed ).
Paste ( Paste ) :
You can paste the last character you copied . Given a number n.
You need to use the least number of operations , Print out exactly... In Notepad n individual A.
The output can print out n individual A The minimum number of operations .
Input format
An integer n.
Output format
An integer , Indicates the minimum number of operations .
Data range
$1\le n\le 10^6$
Topic link ： Notepad

Ideas ：
   Let's first consider that the input number is a prime number n The situation of ： Prime numbers must be copied first 1 Time , Then paste n - 1 Time .( for example 7 Only copy 1 Time , Paste 6 Time to get , You can push it once on the draft book )
   So for the case of composite numbers , We can decompose the prime factor , Then keep pasting to get .
for instance ：
  24 = 2² * 3². Let's copy and paste to get 2, Copy 1 Time , Paste 2 - 1 Time , obtain 2² You have to copy again 1 Time , Paste 2-1 Time , And then put 2² As a whole , Copy 1 Time , Paste 3-1 Time , Copy again 1 Time , Paste 2-1 Time . common 2x2+3x2 = 10 Time

Code ：

import java.util.Scanner;
public class Main {
    
	public static void main(String[] args) {
    
		int n = new Scanner(System.in).nextInt();
		int res = 0;;
		for (int i = 2; i <= n; i++) {
    
			int s = 0;		// Look at how many times the prime factor has been used 
			while (n % i == 0) {
    
				s++;
				n /= i;
			}
			if (s > 0) {
    
				res += i * s;
			}
		}
		System.out.println(res);
	}
}