#include <iostream>
using namespace std;
int n;
int main() {
  cin>>n;
  if(n%2==1){
  	cout<<n/2+1;
  }
  else cout<<(n/2)+(n/2+1);
    return 0;
}    
/**************************************************************
	Problem: 1558
	User: wangyousi
	Language: C++
	Result: Accepted
	Time:46 ms
	Memory:2072 kb
****************************************************************/