#include using namespace std; #define FOR(i,a,b) for(int i=(a);i<(b);i++) #define REP(i,n) FOR(i,0,n) #define ALL(v) (v).begin(),(v).end() #define fi first #define se second template inline bool chmax(A &a, B b) { if (a inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; } typedef long long ll; typedef pair pii; typedef pair pll; typedef pair pip; const ll INF = 1e9+100; const ll MOD = 1e9+7; const double EPS = 1e-10; const bool debug = 0; //---------------------------// ll N; ll ncr(ll n, ll r) { if (n < r || n < 0 || r < 0) return 0; ll res = 1, c = 1; for (ll i = n; i >= n - r + 1; i--) { res *= i; if (c <= r) res /= c++; } while (c <= r) res /= c++; return res; } int main() { cin >> N; if (N <= 8) { ll ans = 0; REP(i, N + 1) if (ncr(N, i) % 2 == 0) ans++; cout << ans << endl; } else cout << N - 3 << endl; return 0; }