#include<iostream>
#include<vector>
using namespace std;

int main(){
    int n, k;
    cin >> n >> k;

    int a;
    for(a = 1;;a++){
        int put = min(k, a)*a;
        if(put >= n)    break;
    }

    vector<vector<char>> ans(a, vector<char>(a, '.'));
    vector<int> col(a, 0);
    for(int i = 0; i < a; i++){
        int row = 0;
        for(int j = 0; j < a; j++){
            if(row == k)    break;
            if(n == 0)  continue;
            if(col[j] == k) continue;
            col[j]++, row++;
            ans[i][j] = '#';
            n--;
        }
    }
    cout << a << endl;
    for(int i = 0; i < a; i++){
        for(int j = 0; j < a; j++){
            cout << ans[i][j];
        }
        cout << endl;
    }
    return 0;
}