#include <bits/stdc++.h>
typedef long long ll;
#define REP(i, n) for(ll i = 0; i < (n); i ++)
const ll MOD = 1000000007LL;
const ll INF = (1LL<<60);
const ll MAX = 505050;
using namespace std;

int main(){
	ll n, k;
	cin >> n >> k;

	ll m = (n+(k*k-1)) / (k*k);
	m *= k;
	string s = "";
	REP(i, m) s += ".";
	vector<string> ans(m, s);
	cout << m << endl;

	ll cnt = 0;
	REP(i, m/k){
		REP(j, k){
			REP(p, k){
				ll x = i * k + j, y = i * k + p;
				ans[x][y] = '#';
				cnt ++;
				if(cnt == n) goto END;
			}
		}
	}
	END:
	REP(i, m){
		cout << ans[i] << endl;
	}
	return 0;
}