#include <iostream>
#include <vector>
using namespace std;

vector<double> fusio(const vector<double>& V1, const vector<double>& V2);

int main()
{
    cout.setf(ios::fixed, ios::floatfield);
    cout.precision(1);

    int n1;
    while (cin >> n1) {
        vector<double> V1(n1);
        for (int i = 0; i < n1; ++i)
            cin >> V1[i];
        int n2;
        cin >> n2;
        vector<double> V2(n2);
        for (int i = 0; i < n2; ++i)
            cin >> V2[i];

        vector<double> res = fusio(V1, V2);
        int n3 = res.size();
        cout << n3 << endl;
        for (int i = 0; i < n3; ++i)
            cout << " " << res[i];
        cout << endl
             << endl;

        for (int r = 0; r < 200; ++r) {
            vector<double> res2 = fusio(V1, V2);
            if (res2 != res)
                cout << "Resultats diferents amb la mateixa entrada!" << endl;
        }
    }
    return 0;
}
