#include <iostream>
#include <cassert>
using namespace std;
char c[1010][1010];
int main(){
	int i,j,n,k;
	cin >> n >> k;
	int m = (n + k - 1)/k;
	while(m*m<n){
		m++;
	}
	cout << m << endl;
	for(i=0;i<m;i++){
		for(j=0;j<m;j++){
			c[i][j] = '.';
		}
	}
	int x = -1;
	for(i=0;i<m;i++){
		int now = 0,las = -1;
		for(j=0;j<2*m;j++){
			if(n>0 && now<k && x<j){
				now++; n--;
				c[i][j%m] = '#';
				las = j%m;
			}
		}
		x = las;
		if(las==m - 1) x = -1;
	}
	for(i=0;i<m;i++){
		for(j=0;j<m;j++){
			cout << c[i][j];
		}
		cout << endl;
	}
}