#line 1 "main.cpp"
#include <iostream>
#include <vector>

using namespace std;
using lint = long long;

void solve() {
    lint n;
    cin >> n;

    if (n >= 7) {
        cout << "2\n";
        return;
    } else if (n >= 5) {
        cout << "4\n";
        return;
    }

    int m = (1 << n);
    int ans = 0;
    for (int b = 0; b < (1 << m); ++b) {
        bool judge = true;

        for (int i = 0; i < m; ++i) {
            if ((~b >> i) & 1) continue;
            for (int j = 0; j < i; ++j) {
                if ((~b >> j) & 1) continue;

                if (__builtin_popcount(i & j) >= 2 ||
                    n - __builtin_popcount(i | j) >= 2) judge = false;
            }
        }

        if (judge) ans = max(ans, __builtin_popcount(b));
    }

    cout << ans << "\n";
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    solve();

    return 0;
}