#include <bits/stdc++.h>
using namespace std;

using ll = long long;
#define FOR(i, m, n) for (int i = (m); i < (n); i++)
#define REP(i, n) FOR(i, 0, n)
#define REP1(i, n) FOR(i, 1, (n) + 1)
#define ALL(c) (c).begin(), (c).end()
template<class T> inline bool chmin(T& a, T b) {if (a > b) {a = b; return true;} return false;}
template<class T> inline bool chmax(T& a, T b) {if (a < b) {a = b; return true;} return false;}
const int MOD = 1000000007;
const int INF = 1000000001;

int main() {
    int n, k;
    cin >> n >> k;
    int x = (n + k - 1) / k;
    cout << x << endl;
    int z = 0;
    int c = 0;
    REP(i, x) {
        REP(j, x) {
            if (c < n && j >= z && j < z + k) {
                cout << "#";
                c++;
            } else if (c < n && i >= x - (k - 1) && j < k - (x - i)) {
                cout << "#";
                c++;
            } else {
                cout << ".";
            }
        }
        cout << endl;
        z++;
    }
}