#include<bits/stdc++.h>
using namespace std;
int main(){
	int n;
	cin>>n;
	if(n%2!=0){
		cout<<n/2+1;
	}else{
		cout<<(n/2)+(n/2+1);
	}
}
/**************************************************************
	Problem: 1558
	User: linzihang
	Language: C++
	Result: Accepted
	Time:39 ms
	Memory:2072 kb
****************************************************************/