#include<bits/stdc++.h>
using namespace std;
using LL = long long;
using ULL = unsigned long long;
#define rep(i,n) for(int i=0; i<(n); i++)

int main() {
    int N, K; cin >> N >> K;
    int R = (N - 1) / K + 1;
    while (R * R < N) R++;
    cout << R << endl;
    rep(y, R) {
        rep(x, R) {
            bool black = false;
            if ((x + y) % R < K) if (N != 0) {
                N--; black = true;
            }
            cout << (black ? "#" : ".");
        }
        cout << endl;
    }

    return 0;
}