#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using P = pair<ll, ll>;
#include <atcoder/modint>
#include <atcoder/scc>
using namespace atcoder;
using mint = modint1000000007;
template<typename T> using V = vector<T>;
template<typename T> using VV = V<V<T>>;
template<typename T> using VVV = VV<V<T>>;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
int main()
{
    int n;
    cin >> n;
    if(n & 1) cout << 1 << endl;
    else cout << 1 + n/2 << endl;
}