//#pragma GCC target("avx2,avx") #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") //#include //using namespace atcoder; //using mint = modint998244353; //using mint = modint1000000007; #include using namespace std; //#include //#include //using namespace __gnu_pbds; //using i128 = __int128_t; using ll = long long; using ull = unsigned long long; using pii = pair; using pll = pair; #define rep(i, n) for(int i = 0; i < (n); ++i) #define all(x) (x).begin(),(x).end() #define SZ(x) ((int)(x).size()) constexpr char ln = '\n'; template inline bool chmax(T1 &a, T2 b) {if (a < b) {a = b; return true;} return false;} template inline bool chmin(T1 &a, T2 b) {if (a > b) {a = b; return true;} return false;} inline int topbit(int x) {return x == 0 ? -1 : 31-__builtin_clz(x);} inline int topbit(long long x) {return x == 0 ? -1 : 63-__builtin_clzll(x);} inline int botbit(int x) {return x == 0 ? 32 : __builtin_ctz(x);} inline int botbit(long long x) {return x == 0 ? 64 : __builtin_ctzll(x);} inline int popcount(int x) {return __builtin_popcount(x);} inline int popcount(long long x) {return __builtin_popcountll(x);} inline int kthbit(long long x, int k) {return (x>>k)&1;} inline void print() {cout << "\n";} template inline void print(const vector &v) { for (auto itr = v.begin(); itr != v.end(); ++itr) cout << *itr << " "; print(); } template inline void print(const T &x, const Args &... args) { cout << x << " "; print(args...); } #ifdef MINATO_LOCAL #define dump(x) cerr << __LINE__ << " : " << #x << " = " << (x) << endl; inline void debug() {cerr << endl;} template inline void debug(const vector &v) { for (auto itr = v.begin(); itr != v.end(); ++itr) cerr << *itr << " "; debug(); } template inline void debug(const T &x, const Args &... args) { cerr << x << " "; debug(args...); } #else #define dump(x) void(0) inline void debug() {} template inline void debug(const vector &v) {} template inline void debug(const T &x, const Args &... args) {} #endif struct Fast_ios {Fast_ios() {cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(20);};} fast_ios; //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// int main() { int N; cin >> N; int ans = 0; for (int i = 0; i*5 <= N; i++) { rep(j,i+1) { if (N-i*5-j*2 < 0) continue; if ((N-i*5-j*2)%3==0) ans++; } } cout << ans << ln; }