// Space optimized CPP implementation of longest
// common substring.

#include <vector>
#include <string>
#include <algorithm>
#include <iostream>


using namespace std;

// Function to find longest common substring.
int LCSubStr(string X, string Y)
{
    // Find length of both the strings.
    int m = X.length();
    int n = Y.length();

    // Variable to store length of longest
    // common substring.
    int result = 0;

    // Matrix to store result of two
    // consecutive rows at a time.
    vector<vector<int>> len(2, vector<int>(n + 1));

    // Variable to represent which row of
    // matrix is current row.
    int currRow = 0;

    // For a particular value of i and j,
    // len[currRow][j] stores length of longest
    // common substring in string X[0..i] and Y[0..j].
    for (int i = 0; i <= m; i++) {
        for (int j = 0; j <= n; j++) {
            if (i == 0 || j == 0) {
                len[currRow][j] = 0;
            }
            else if (X[i - 1] == Y[j - 1]) {
                len[currRow][j] = len[1 - currRow][j - 1] + 1;
                result = max(result, len[currRow][j]);
            }
            else {
                len[currRow][j] = 0;
            }
        }

        // Make current row as previous row and previous
        // row as new current row.
        currRow = 1 - currRow;
    }

    return result;
}

int main() {
    short n;
    cin >> n;

    string X;
    for (int i = 0; i < n; ++i) {
        short tmp;
        cin >> tmp;
        X.push_back(static_cast<unsigned char> (tmp));
    }

    short k;
    cin >> k;

    string Y;
    for (int i = 0; i < k; ++i) {
        short tmp;
        cin >> tmp;
        Y.push_back(static_cast<unsigned char> (tmp));
    }

    cout << LCSubStr(X, Y);

    return 0;
}