#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m;
  cin >> n >> m;
  if (n <= 6) {
    cout << m << endl;
    return 0;
  }
  int mark[8][8] = {0}, i, j, deg[8] = {0}, a, k;
  for (i = 0; i < m; i++) {
    int x, y;
    cin >> x >> y;
    mark[x][y] = 1;
    mark[y][x] = 1;
    deg[x]++;
    deg[y]++;
  }
  int max = INT_MIN;
  for (i = 1; i <= 7; i++) {
    int v[8] = {0}, c = 0, count = 0;
    count = m - deg[i];
    for (j = 1; j <= 7; j++) {
      if (j == i) continue;
      for (k = 1; k <= 7; k++) {
        if (k == i) continue;
        if (mark[j][k] == 0 && mark[j][i] == 1) v[k]++;
      }
    }
    sort(v, v + 8);
    for (j = 1; j <= 7; j++) {
      if (mark[i][j] == 1) c++;
    }
    if (c < v[7])
      count += c;
    else
      count += v[7];
    if (count > max) max = count;
  }
  cout << max << endl;
  return 0;
}
