#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
using ll =  long long ;
using P = pair<int,int> ;
const ll INF = 1e18;
const int MOD = 1000000007;

int main(){
    int n,k;
    cin >> n >> k;
    int p = n / (k * k);
    int q = n % (k * k);
    int r;
    rep(i,k+1){
        if(i * i >= q){
            r = i;
            break;
        }
    }
    int m = p * k + r;
    vector<vector<char>> ans(m,vector<char>(m,'.'));
    int cnt = 0;
    rep(i,m)rep(j,m){
        if(i/k == j/k && i/k < p) ans[i][j] = '#',cnt ++;
        else if(i/k == j/k && cnt < n) ans[i][j] = '#',cnt ++;
    }
    cout << m << endl;
    rep(i,m){
        rep(j,m) cout << ans[i][j] ;
        cout << endl;
    }
    return 0;
}