#include #define rep(i, n) for (int i = 0; i < int(n); i++) #define rrep(i, n) for (int i = int(n) - 1; i >= 0; i--) #define reps(i, n) for (int i = 1; i <= int(n); i++) #define rreps(i, n) for (int i = int(n); i >= 1; i--) #define repc(i, n) for (int i = 0; i <= int(n); i++) #define rrepc(i, n) for (int i = int(n); i >= 0; i--) #define repi(i, a, b) for (int i = int(a); i < int(b); i++) #define repic(i, a, b) for (int i = int(a); i <= int(b); i++) #define each(x, y) for (auto &x : y) #define all(a) (a).begin(), (a).end() #define bit(b) (1ll << (b)) using namespace std; using i32 = int; using i64 = long long; using u64 = unsigned long long; using f80 = long double; using vi32 = vector; using vi64 = vector; using vu64 = vector; using vf80 = vector; using vstr = vector; inline void yes() { cout << "Yes" << '\n'; exit(0); } inline void no() { cout << "No" << '\n'; exit(0); } inline i64 gcd(i64 a, i64 b) { if (min(a, b) == 0) return max(a, b); if (a % b == 0) return b; return gcd(b, a % b); } inline i64 lcm(i64 a, i64 b) { return a / gcd(a, b) * b; } inline u64 xorshift() { static u64 x = 88172645463325252ull; x = x ^ (x << 7); return x = x ^ (x >> 9); } void solve(); int main() { ios::sync_with_stdio(0); cin.tie(0); cout << fixed << setprecision(16); solve(); return 0; } template class pqasc : public priority_queue, greater> {}; template class pqdesc : public priority_queue, less> {}; template inline void amax(T &x, T y) { if (x < y) x = y; } template inline void amin(T &x, T y) { if (x > y) x = y; } template inline T power(T x, i64 n, T e = 1) { T r = e; while (n > 0) { if (n & 1) r *= x; x *= x; n >>= 1; } return r; } template istream& operator>>(istream &is, vector &v) { each(x, v) is >> x; return is; } template ostream& operator<<(ostream &os, vector &v) { rep(i, v.size()) { if (i) os << ' '; os << v[i]; } return os; } template istream& operator>>(istream &is, pair &p) { is >> p.first >> p.second; return is; } template ostream& operator<<(ostream &os, pair &p) { os << p.first << ' ' << p.second; return os; } void solve() { int N, M; cin >> N >> M; vector> w(N, vector(N, 1e9)); rep(i, N) w[i][i] = 0; rep(i, M) { int a, b; cin >> a >> b; w[a][b] = w[b][a] = 1; } rep(k, N) rep(i, N) rep(j, N) amin(w[i][j], w[i][k] + w[k][j]); int ans = 0; set> tu; rep(i, N) rep(j, N) rep(k, N) rep(l, N) { set se; se.insert(i); se.insert(j); se.insert(k); se.insert(l); vector v; each(s, se) v.push_back(s); if (tu.count(make_tuple(v[0], v[1], v[2], v[3]))) continue; if (se.size() != 4) continue; if (w[i][j] != 1) continue; if (w[i][k] != 2) continue; if (w[i][l] != 1) continue; if (w[j][k] != 1) continue; if (w[j][l] != 2) continue; if (w[k][l] != 1) continue; ans++; tu.emplace(v[0], v[1], v[2], v[3]); } cout << ans << '\n'; }