#include #include using namespace std; using namespace atcoder; using ll = long long; using ull = unsigned long long; using ld = long double; using P = pair; using tp = tuple; template using vec = vector; template using vvec = vector>; #define all(hoge) (hoge).begin(), (hoge).end() #define en '\n' #define rep(i, m, n) for(ll i = (ll)(m); i < (ll)(n); ++i) #define rep2(i, m, n) for(ll i = (ll)(n)-1; i >= (ll)(m); --i) #define REP(i, n) rep(i, 0, n) #define REP2(i, n) rep2(i, 0, n) constexpr long long INF = 1LL << 60; constexpr int INF_INT = 1 << 25; // constexpr long long MOD = (ll)1e9 + 7; constexpr long long MOD = 998244353LL; static const ld pi = 3.141592653589793L; #pragma GCC target("avx2") #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") template inline bool chmin(T &a, T b) { if(a > b) { a = b; return true; } return false; } template inline bool chmax(T &a, T b) { if(a < b) { a = b; return true; } return false; } struct Edge { int to, rev; ll cap; Edge(int _to, int _rev, ll _cap) : to(_to), rev(_rev), cap(_cap) {} }; typedef vector Edges; typedef vector Graph; void add_edge(Graph &G, int from, int to, ll cap, bool revFlag, ll revCap) { G[from].push_back(Edge(to, (int)G[to].size(), cap)); if(revFlag) G[to].push_back(Edge(from, (int)G[from].size() - 1, revCap)); } void solve() { ll n; cin >> n; vec ps; ll n3 = n * 3; vec is_p(n3 + 1, 1); is_p[0] = is_p[1] = 0; for(ll i = 2; i * i <= n3; i++) { if(is_p[i]) { for(ll j = 2; i * j <= n3; j++) { is_p[i * j] = 0; } } } rep(i, 2, n + 1) { if(is_p[i]) ps.push_back(i); } vec f = is_p; f.resize(n + 1); auto f3 = convolution_ll(convolution_ll(f, f), f); ll ans = 0; REP(i, f3.size()) { if(is_p[i]) ans += f3[i]; } for(auto p1 : ps) { for(auto p2 : ps) { if(is_p[p1 * 2 + p2]) { ans -= 3; } } } ans /= 6; cout << ans << en; } int main() { ios::sync_with_stdio(false); cin.tie(0); cout.tie(0); // cout << fixed << setprecision(10); // ll t; // cin >> t; // REP(i, t - 1) { // solve(); // } solve(); return 0; }