import java.util.*;

public class Main{
    public static void main(String[] args) throws Exception{
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        
        if(N % 2 == 1){
            System.out.println(1);
        }else{
            System.out.println(N / 2 + 1);
        }
    }
}