SOSdp.cpp

// ref: https://codeforces.com/blog/entry/45223
// implementation for https://codeforces.com/problemset/problem/383/E

const int N = 1, LN = 24;

vector<int> F(1 << LN, 0);
vector<int> val(LN + 1);

void compute() {
    val[0] = 1;
    for (int i = 1; i <= LN; ++i)
        val[i] = val[i - 1] * 2ll;
}

void solve() {
    int n;
    cin >> n;

    vector<int> v(n, 0);
    string s;
    for (int i = 0; i < n; ++i) {
        cin >> s;

        for (int j = 0; j < 3; ++j)
            v[i] |= val[s[j] - 'a'];
    }

    for (int i = 0; i < n; ++i)
        ++F[v[i]];

    for (int j = 0; j < LN; ++j) {
        for (int i = 0; i < val[LN]; ++i) {
            if (i & val[j])
                F[i] += F[i ^ val[j]];
        }
    }

    int ans = 0, tmp;
    for (int i = 1; i < val[LN]; ++i) {
        tmp = n - F[(val[LN] - 1) ^ i];
        ans ^= (tmp * tmp);
    }

    cout << ans;
}