#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
vector<vector<char>> ans(5555, vector<char>(5555, '.'));
signed main() {
  ios::sync_with_stdio(false); cin.tie(0);
  int n, k;
  cin >> n >> k;
  int cur = 0;
  int row = 0, col = 0;
  while (cur < n) {
    int c = 1;
    while (c <= k && cur + c * c <= n) c++;
    c--;
    for (int i = 0; i < c; i++) {
      for (int j = 0; j < c; j++) {
        if (cur++ < n) ans[row + i][col + j] = '#';
      }
    }
    row += c;
    col += c;
  }
  int x = 0, y = 0;
  for (int i = 0; i < 5555; i++) for (int j = 0; j < 5555; j++) {
    if (ans[i][j] == '#') {
      x = max(x, i);
      y = max(y, j);
    }
  }
  cout << max(x, y) + 1 << '\n';
  for (int i = 0; i <= max(x, y); i++) {
    for (int j = 0; j <= max(x, y); j++) {
      cout << ans[i][j];
    }
    cout << '\n';
  }
  return 0;
}