#include <iostream>
#include <cstdio>
#include <cmath>

using namespace std;

const int N = 1010;

int n, k, m;
char ch[N][N];

int main() {
    // freopen("paint.in", "r", stdin);
    // freopen("paint.out", "w", stdout);y

    scanf("%d%d", &n, &k);

    m = max((n + k - 1) / k, (int) ceil(sqrt(n)));
    for (int i = 1; i <= m; ++i) {
        for (int j = 1; j <= m; ++j) {
            ch[i][j] = '.';
        }
    }
    for (int i = 1; i <= m && n; ++i) {
        int y = i;
        for (int j = 1; j <= m && n; ++j) {
            --n;
            ch[j][y] = '#';
            y %= m;
            ++y;
        }
    }

    printf("%d\n", m);
    for (int i = 1; i <= m; ++i) {
        for (int j = 1; j <= m; ++j) {
            printf("%c", ch[i][j]);
        }
        puts("");
    }

    return 0;
}