#include <iostream>
#include <stack>
#include <vector>

using pii = std::pair<int, int>;
using ll = long long;

int main() {
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(nullptr);

    int n, m;
    std::cin >> n;
    std::vector<ll> a(n + 1);
    for (int i = 1; i <= n; ++i)
        std::cin >> a[i];

    std::cin >> m;
    std::vector<ll> b(m + 1);
    for (int i = 1; i <= m; ++i)
        std::cin >> b[i];

    std::vector<std::vector<int>> dp(n + 1, std::vector<int>(m + 1, 0));

    std::vector<std::vector<pii>> path(n + 1, std::vector<pii>(m + 1, {0, 0}));

    for (int i = 1; i <= n; ++i) {

        int maxlen = 0;

        int pk = 0;

        for (int j = 1; j <= m; ++j) {

            dp[i][j] = dp[i - 1][j];
            path[i][j] = {i - 1, j};

            if (a[i] == b[j]) {
                if (maxlen + 1 > dp[i][j]) {
                    dp[i][j] = maxlen + 1;
                    path[i][j] = {i - 1, pk};
                }
            }

            if (b[j] < a[i]) {
                if (dp[i - 1][j] > maxlen) {
                    maxlen = dp[i - 1][j];
                    pk = j;
                }
            }
        }
    }

    int maxlen = 0;
    int endj = 0;

    for (int j = 1; j <= m; ++j) {
        if (dp[n][j] > maxlen) {
            maxlen = dp[n][j];
            endj = j;
        }
    }

    std::cout << maxlen << "\n";

    if (maxlen > 0) {
        std::stack<ll> res;
        int curri = n;
        int currj = endj;

        while (curri > 0 && currj > 0) {
            pii prev = path[curri][currj];

            if (dp[curri][currj] > dp[prev.first][prev.second] && prev.second != currj) {
                res.push(a[curri]);
            }

            curri = prev.first;
            currj = prev.second;
        }

        bool first = true;
        while (!res.empty()) {
            if (!first) {
                std::cout << " ";
            }
            std::cout << res.top();
            res.pop();
            first = false;
        }
        std::cout << "\n";
    }
}