#include <iostream>
#include <cstdio>
#include <cstring>
#include <vector>
#include <deque>
#include <queue>
#include <array>
#include <set>
#include <map>
#include <cmath>
#include <complex>
#include <algorithm>
#include <numeric>
#include <utility>
#include <tuple>
#include <functional>
#include <bitset>
#include <cstdint>
#include <cassert>
#include <random>

using namespace std;
using i64 = int64_t;
using i32 = int32_t;

char a[1001][1001];
int main() {
    int n, k;
    cin >> n >> k;
    int p = n / (k * k), q = n % (k * k);
    int r = 0;
    while (r * r < q) ++r;

    for (int i = 0; i < k * p + r; ++i) {
        for (int j = 0; j < k * p + r; ++j) {
            a[i][j] = '.';
        }
    }
    for (int b = 0; b < p; ++b) {
        for (int i = k * b; i < k * (b + 1); ++i) {
            for (int j = k * b; j < k * (b + 1); ++j) {
                a[i][j] = '#';
            }
        }
    }
    int c = 0;
    for (int i = k * p; i < k * p + r; ++i) {
        for (int j = k * p; j < k * p + r; ++j) {
            ++c;
            if (c <= q) a[i][j] = '#';
        }
    }
    cout << k * p + r << '\n';
    for (int i = 0; i < k * p + r; ++i) {
        cout << a[i] << '\n';
    }
    return 0;
}