void solve()
{
    ll n;
    cin >> n;
    vector<ll> A(n);
    for (ll i = 0; i < n; i++)
        cin >> A[i];
    sort(A.begin(), A.end());
    ll l = 0, r = 0, ans = 0;
    while (r < n)
    {
        while (l < r && A[r] - A[l] > 5)
        {
            l++;
        }
        ans = max(ans, r - l + 1);
        r++;
    }
    cout << ans << endl;
    return;
}