#include <bits/stdc++.h>
using namespace std;
const long long inf = (1ll << 62) - 1;
const long long mod = 1e9 + 7;
const long long N = 1005;
const long double pi = 3.14159265358979323846;
long long bPow(long long a, long long b) {
  long long res = 1;
  while (b) {
    if (b & 1) {
      res = (res * a) % mod;
    }
    b >>= 1;
    a = (a * a) % mod;
  }
  return res % mod;
}
long long gcd(long long a, long long b) {
  if (a < b) swap(a, b);
  if (b == 0) return a;
  return gcd(b, a % b);
}
vector<long long> fact(N, 0ll);
void factorial() {
  fact[0] = 1, fact[1] = 1;
  for (long long i = 2; i < N; i++) {
    fact[i] = (fact[i - 1] * i) % mod;
  }
}
long long ncr(long long n, long long r) {
  if (r > n) return 0;
  long long ans = fact[n] % mod;
  ans *= bPow(fact[r], mod - 2) % mod;
  ans %= mod;
  ans *= bPow(fact[n - r], mod - 2) % mod;
  ans %= mod;
  return ans;
}
vector<long long> primes(N, -1), factors(N, 2);
void sieve() {
  iota(primes.begin(), primes.end(), 0);
  for (long long i = 2; i * i <= N; ++i) {
    if (primes[i] == i) {
      for (long long j = 2 * i; j < N; j += i) {
        primes[j] = i;
        factors[j]++;
      }
    }
  }
}
long long add(long long a, long long b) { return ((a + b) % mod + mod) % mod; }
long long mul(long long a, long long b) { return ((a * b) % mod + mod) % mod; }
void getDomino(vector<set<long long>>& d) {
  for (long long i = 0; i < 7; ++i) {
    for (long long j = i; j < 7; ++j) {
      d[i].insert(j);
    }
  }
}
void solve() {
  long long n, m;
  cin >> n >> m;
  vector<vector<bool>> adj(n + 1, vector<bool>(n + 1, false));
  for (long long i = 0; i < m; ++i) {
    long long u, v;
    cin >> u >> v;
    adj[u][v] = true, adj[v][u] = true;
  }
  if (n <= 6) {
    cout << m << endl;
    return;
  }
  long long cant = 100;
  for (long long i = 1; i <= n; ++i) {
    for (long long j = i + 1; j <= n; ++j) {
      long long ct = 0;
      for (long long k = 1; k <= n; ++k) {
        if (adj[i][k] and adj[j][k]) ct++;
      }
      cant = min(cant, ct);
    }
  }
  cout << m - cant << endl;
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long tc = 1, test = 1;
  while (tc--) {
    solve();
  }
}
