#include <bits/stdc++.h>
using namespace std;
const unsigned long long int hell = 100005;
bool comp(const pair<string, unsigned long long int> &a,
          const pair<string, unsigned long long int> &b) {
  return a.second > b.second;
}
unsigned long long int binpow(unsigned long long int a,
                              unsigned long long int b) {
  unsigned long long int res = 1;
  while (b > 0) {
    if (b & 1) res = res * a;
    a = a * a;
    b >>= 1;
  }
  return res;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  unsigned long long int n;
  cin >> n;
  cout << n / 2 + 1;
  return 0;
}
