#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: linmiaoling
	Language: C++
	Result: Accepted
	Time:54 ms
	Memory:2072 kb
****************************************************************/