#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: 1588
	User: wengsihan
	Language: C++
	Result: Wrong Answer
****************************************************************/