#include<bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int,int> P;

#define p_ary(ary,a,b,i) do { cout << "["; for (int (i) = (a);(i) < (b);++(i)) cout << ary[(i)] << ((b)-1 == (i) ? "" : ", "); cout << "]\n"; } while(0)
#define p_map(map,it) do {cout << "{";for (auto (it) = map.begin();;++(it)) {if ((it) == map.end()) {cout << "}\n";break;}else cout << "" << (it)->first << "=>" << (it)->second << ", ";}}while(0)

int main() {
    int n,k;
    cin >> n >> k;
    int m = (n+k-1)/k;
    cout << m << endl;
    vector<int> x(m,0),y(m,0);
    for (int i = 0;i < m;++i) {
        for (int j = 0;j < m;++j) {
            if (n && x[i] < k && y[j] < k) cout << "#",n--,x[i]++,y[j]++;
            else cout << ".";
        }
        cout << "\n";
    }
}