#include <iostream>
#include <cstdio>

using namespace std;

int n, k, m;

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

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

    int row = (n - 1) / k + 1;
    if (row % k == 1) { // 列数要特判
        m = max(row, row - 1 + (n % (k * k)));
    } else {
        m = max(row, (row + k - 1) / k * k);
    }

    printf("%d\n", m);
    int finished = 0;
    for (int i = 1; i <= m; ++i) {
        int l, r;
        if (finished + k <= n) {
            l = (i - 1) / k * k + 1, r = l + k - 1;
            finished += k;
        } else {
            l = (i - 1) / k * k + 1, r = l + (n - finished) - 1;
        }
        for (int j = 1; j <= l - 1; ++j) printf(".");
        for (int j = l; j <= r; ++j) printf("#");
        for (int j = r + 1; j <= m; ++j) printf(".");
        puts("");
    }


    return 0;
}