#include<bits/stdc++.h>
using namespace std;
int main(){ 
	int n,m;
	cin>>n;
	if(n%2==0){
		m=n/2;
		cout<<m+m+1;
	}else{
		cout<<(n+1)/2;
	}
}
/**************************************************************
	Problem: 1558
	User: wangyiyang
	Language: C++
	Result: Accepted
	Time:50 ms
	Memory:2072 kb
****************************************************************/