#include <bits/stdc++.h>
using namespace std;
int main(void){
    int N, K; cin >> N >> K;
    int cnt = 0;
    int add_cnt = 1;
    int n;
    for (n = 0; cnt < N; n++) {
        if (n % K == 0) {
            add_cnt = 1;
        } else {
            add_cnt += 2;
        }
        cnt += add_cnt;
    }

    cout << n << endl;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            if (i / K * K <= j && j < i / K * K + K) cout << "#";
            else cout << ".";
        }
        cout << endl;
    }
}