#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
//const int INF = 1e9;
//const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define endl "\n"
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
int sqrt_(int n) {
	rep(i, 100) {
		if (i*i >= n)return i;
	}
}
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n, k; cin >> n >> k;
	int m;
	if (n >= k * k)m = (n + (k - 1)) / k;
	else m = sqrt_(n);
	vector<string>ans(m);
	rep(i, m)rep(j, m)ans[i] += '.';
	rep(i, m) {
		rep(j, min(m, k)) {
			int idx = (i + j) % m;
			if (!n)continue;
			ans[i][idx] = '#';
			n--;
		}
	}
	cout << m << endl;
	rep(i, m)cout << ans[i] << endl;
	return 0;
}