#include <iostream>
#include <map>
#include <cmath>
#include <queue>
#include <vector>
#include <string>
#include <algorithm>
#include <functional>
using namespace std;

int main() {
	long long N;
	cin >> N;
	if (N % 2 == 0) cout << (N / 2) + 1 << endl;
	else cout << "1" << endl;
	return 0;
}