#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using ull=unsigned long long;
#define rep(i,n) for(int i=0; i<(n); i++)

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