import java.util.*;
import java.io.*;

public class Main {
	public static void main (String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int n = Integer.parseInt(br.readLine());
		if (n % 2 == 0) {
		    System.out.println(n / 2 + 1);
		} else {
		    System.out.println(1);
		}
   }
}