#include <bits/stdc++.h>
#define all(x) begin(x),end(x)

using namespace std;


struct T {
    std::shared_ptr<vector<int>> a;

    T(vector<int>&& a) : a(std::make_shared<vector<int>>(std::move(a))) {}

    const int* begin() {
        return a->data();
    }

    const int* end() {
        return a->data() + a->size();
    }

};

vector<int> f(int n) {
    vector<int> ans(n);
    iota(all(ans), 0);
    return ans;
}

int main() {
    int n;
    cin >> n;
    int ans = 0;
    for (auto& x : T(f(n))) {
        ans ^= x;
    }
    cout << ans << '\n';
}