#define _USE_MATH_DEFINES
#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define MT make_tuple
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
#define RT return
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;
using vll = vector<ll>;

char A[1010][1010];

void solve() {
    MEM(A, '.');

    int N, K;
    cin >> N >> K;
    
    int M = 0;
    while (N > 0) {
        if (N < K*K) {
            int r = 1;
            while (r*r < N)++r;
            [&] {
                rep(i, r)rep(j, r) {
                    A[M + i][M + j] = '#';
                    if (!--N)return;
                }
            }();
            M += r;
        } else {
            rep(i, K)rep(j, K)A[M + i][M + j] = '#';
            N -= K * K;
            M += K;
        }
    }

    cout << M << endl;
    rep(i, M) {
        rep(j, M)cout << A[i][j];
        cout << endl;
    }
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout << fixed << setprecision(15);
	solve();
	return 0;
}