abc089_c - March

using namespace std;
using ll = long long;
using ii = pair<int, int>;
using vi = vector<int>;
int main(void)
{
    ios::sync_with_stdio(false), cin.tie(NULL);
    const string march = "MARCH";
    array<ll, 5> cnt;
    fill(begin(cnt), end(cnt), 0);
    int n;
    cin >> n;
    while (n--)
    {
        string s;
        cin >> s;
        if (auto it = find(begin(march), end(march), s[0]); it != end(march))
            cnt[distance(begin(march), it)]++;
    }
    ll ans = 0;
    for (int i = 0; i < 3; ++i)
        for (int j = i + 1; j < 4; ++j)
            for (int k = j + 1; k < 5; ++k)
                ans += cnt[i] * cnt[j] * cnt[k];
    cout << ans << endl;
    return 0;
}