kupc2016B.cpp

signed main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);

    int n, k;
    cin >> n >> k;
    vi cnt(26);
    rep(i, n) {
        string s;
        cin >> s;
        cnt[s[0] - 'A']++;
    }

    int ans = 0;
    while (true) {
        sort(rall(cnt));
        rep(i, k) {
            if (cnt[i] == 0) {
                cout << ans << endl;
                return 0;
            }
            cnt[i]--;
        }
        ans++;
    }
}