#include #include #include #include #include #include #include #include #define rep(i, a, b) for (int i = int(a); i < int(b); i++) using namespace std; using ll = long long int; // NOLINT using P = pair; // clang-format off #ifdef _DEBUG_ #define dump(...) do{ cerr << __LINE__ << ":\t" << #__VA_ARGS__ << " = "; debug_print(__VA_ARGS__); } while(false) template void debug_print(const T &t, const Ts &...ts) { cerr << t; ((cerr << ", " << ts), ...); cerr << endl; } #else #define dump(...) do{ } while(false) #endif template vector make_v(size_t a, T b) { return vector(a, b); } template auto make_v(size_t a, Ts... ts) { return vector(a, make_v(ts...)); } template bool chmin(T &a, const T& b) { if (a > b) {a = b; return true; } return false; } template bool chmax(T &a, const T& b) { if (a < b) {a = b; return true; } return false; } template void print(const T& t, const Ts&... ts) { cout << t; ((cout << ' ' << ts), ...); cout << '\n'; } template void input(Ts&... ts) { (cin >> ... >> ts); } template istream &operator,(istream &in, T &t) { return in >> t; } struct Inf { template constexpr operator T() { return numeric_limits::max() / 2; } }; // clang-format on int main() { cin.tie(nullptr); ios::sync_with_stdio(false); int n, m; cin >> n >> m; const int inf = Inf(); auto v = make_v(n, n, inf); rep(i, 0, n) v[i][i] = 0; rep(i, 0, m) { int a, b; cin >> a >> b; a--; b--; v[a][b] = v[b][a] = 1; } rep(k, 0, n) { rep(i, 0, n) { rep(j, 0, n) { chmin(v[i][j], v[i][k] + v[k][j]); } } } auto check = [&](int a, int b) { if (v[a][b] == 2) return false; return true; }; int ans = 0; rep(i, 0, n) { rep(j, i + 1, n) { if (!check(i, j)) continue; rep(k, j + 1, n) { if (!check(i, k) || !check(j, k)) continue; ans++; } } } print(ans); return 0; }