#include<iostream>
using namespace std;
int N,K;
main()
{
	cin>>N>>K;
	int M;
	if(N>=K*K)M=(N+K-1)/K;
	else
	{
		while(M*M<N)M++;
	}
	cout<<M<<endl;
	for(int i=0;i<M;i++)
	{
		for(int j=0;j<M;j++)
		{
			cout<<((i+K<=M?i<=j&&j<i+K:i<=j||j+M<i+K)&&N-->0?'#':'.');
		}
		cout<<endl;
	}
}