#include "bits/stdc++.h"
using namespace std;
#define int long long
#define FOR(i, a, b) for(int i=(a);i<(b);i++)
#define RFOR(i, a, b) for(int i=(b-1);i>=(a);i--)
#define REP(i, n) for(int i=0; i<(n); i++)
#define RREP(i, n) for(int i=(n-1); i>=0; i--)
#define ALL(a) (a).begin(),(a).end()
#define UNIQUE_SORT(l) sort(ALL(l)); l.erase(unique(ALL(l)), l.end());
#define CONTAIN(a, b) find(ALL(a), (b)) != (a).end()
#define array2(type, x, y) array<array<type, y>, x>
#define vector2(type) vector<vector<type> >
#define out(...) printf(__VA_ARGS__)

int dxy[] = {0, 1, 0, -1, 0};

void solve();
signed main()
{
#if DEBUG
    std::ifstream in("input.txt");
    std::cin.rdbuf(in.rdbuf());
#endif
    cin.tie(0);
    ios::sync_with_stdio(false);
    solve();
    return 0;
}

/*================================*/

int N,K;

void solve() {
    cin>>N>>K;
    
    typedef pair<int,int> p;
    vector<p> V;
    int remain = N;
    int offset = 0;
    while(remain) {
        int v = min(K,(int)ceil(sqrt(remain)));
        REP(i,v) {
            int num = min(remain, v);
            V.push_back(p(offset, num));
            remain -= num;
        }
        offset += v;
    }
    cout << V.size() << endl;
    REP(i,V.size()) {
        REP(j,V.size()){
            char c = (V[i].first <= j && j < V[i].second+V[i].first) ? '#' : '.';
            cout << c;
        }
        cout << endl;
    }
}