#define _USE_MATH_DEFINES #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; typedef long long ll; typedef unsigned long long ull; typedef pair i_i; typedef pair ll_i; typedef pair d_i; typedef pair ll_ll; typedef pair d_d; struct edge { int u, v; ll w; }; ll MOD = 1000000007; ll _MOD = 1000000009; double EPS = 1e-9; bool is_uruu(ll y) { if (y % 400 == 0) return true; if (y % 100 == 0) return false; if (y % 4 == 0) return true; return false; } int main() { int Y = 0, X = 0, K = 0; for (;;) { if (Y > 0 && Y % 400 == 0 && X == 0) break; if (X == 0) K++; X += is_uruu(Y + 1) ? 2 : 1; X %= 7; Y++; } ll N; cin >> N; int x = 0; ll k = 0; for (ll y = 2014; y <= N;) { if (y % 400 == 0 && x == 0 && y + Y <= N) { k += K; y += Y; } else { if (x == 0) k++; x += is_uruu(y + 1) ? 2 : 1; x %= 7; y++; } } cout << k - 1 << endl; }