#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[2010][2010];

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

    int N, K, M = 1;
    cin >> N >> K;
    if (N <= K * K) {
        while (M*M < N)M++;
        [&] {
            int cnt = 0;
            rep(y, M)rep(x, M) {
                if (cnt++ == N)return;
                A[y][x] = '#';
            }
        }();
    } else {
        M = (N + K - 1) / K;
        [&] {
            int cnt = 0;
            rep(y, M) for (int x = y, i = 0; i < K; x = (x + 1) % M, i++) {
                if (cnt++ == N)return;
                A[y][x] = '#';
            }
        }();
    }

    cout << M << endl;
    rep(y, M) {
        rep(x, M)cout << A[y][x];
        cout << endl;
    }
}

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