void solve() {
    int N; cin >> N;
    vector<string> P(N); F0R(i, N) cin >> P[i];
    vector<vi> pos(N);
    F0R(i, N) {
        F0R(j, sz(P[i])) {
            if (P[i][j] == '*') pos[i].pb(j);
        }
    }


    string st, en;
    F0R(s, N) {
        string cur; F0R(i, pos[s][0]) cur += P[s][i];
        if (sz(cur) > sz(st)) {
            swap(cur, st);
        }
        F0R(i, sz(cur)) if (cur[i] != st[i]) {
            cout << '*' << nl; return;
        }
    }

    F0R(s, N) {
        string cur; FORd(i, pos[s][sz(pos[s])-1] + 1, sz(P[s])) {
            cur += P[s][i];
        }
        if (sz(cur) > sz(en)) {
            swap(cur, en);
        }
        F0R(i, sz(cur)) if (cur[i] != en[i]) {
            cout << '*' << nl; return;
        }
    }

    string ans = st;
    F0R(i, N) {
        F0R(j, sz(P[i])) {
            if (P[i][j] != '*') ans += P[i][j];
        }
    }
    reverse(all(en)); ans += en;
    cout << ans << nl;

}