#include <iostream>
using namespace std;

int main() {
    int n;
    cin >> n;
    if (n % 2 != 0) {
        cout << (n / 2 + 1);
    } else {
        cout << (n / 2 + n / 2 + 1);
    }
    return 0;
}
/**************************************************************
	Problem: 1558
	User: fuhoubin
	Language: C++
	Result: Accepted
	Time:62 ms
	Memory:2072 kb
****************************************************************/