#include <bits/stdc++.h>
using namespace std;

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

    constexpr int n = 666;
    constexpr int m = (n - 3) / 4;
    constexpr int side = 4 * m + 3;

    vector<string> base(side, string(side, '.'));
    const auto add_plus = [&](int x, int y) {
        const int row = 2 * x + 1;
        const int column = 2 * y + 1;
        base[row][column] = '#';
        base[row - 1][column] = '#';
        base[row + 1][column] = '#';
        base[row][column - 1] = '#';
        base[row][column + 1] = '#';
    };

    for (int x = 0; x <= 2 * m; ++x) {
        if (x % 2 == 0) {
            for (int y = m; y <= 2 * m; ++y) add_plus(x, y);
        } else {
            for (int y = 0; y <= m; ++y) add_plus(x, y);
        }
    }

    vector<string> changed = base;
    changed[2][1] = '.';

    cout << n << '\n';
    const string padding(n - side, '.');
    for (const auto* piece : {&base, &base, &changed}) {
        for (const string& row : *piece) cout << row << padding << '\n';
        for (int row = side; row < n; ++row) cout << string(n, '.') << '\n';
    }
    return 0;
}