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

void solve() {
    int n, k;
    std::cin >> n >> k;

    int m = 0;
    while (m * k < n || m * m < n) ++m;

    std::vector<std::string> ans(m, std::string(m, '.'));
    for (int i = 0; i < m; ++i) {
        for (int j = 0; j < m; ++j) {
            if (n == 0) continue;
            ans[j][(i + j) % m] = '#';
            --n;
        }
    }

    std::cout << m << "\n";
    for (const auto& s : ans) std::cout << s << "\n";
}

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

    solve();

    return 0;
}