#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
 
bool inside(ll i, ll j, ll r, ll c)
{
  return (i < r && j < c && i >= 0 && j >= 0);
}
 
pair<ll, ll> directions[4] = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}};
 
void solve()
{
  int n, m;
  cin >> n >> m;
 
  vector<vector<char>> arr(n, vector<char>(m, '#'));
 
  int s1 = -1, s2 = -1;
 
  for (int i = 0; i < n; i++)
    for (int j = 0; j < m; j++)
    {
      cin >> arr[i][j];
      if (arr[i][j] == 'A')
      {
        s1 = i;
        s2 = j;
      }
    }
 
  vector<vector<bool>> vis(n, vector<bool>(m, false));
 
  map<pair<int, int>, char> hash;
 
  hash[{0, 1}] = 'R';
  hash[{1, 0}] = 'D';
  hash[{0, -1}] = 'L';
  hash[{-1, 0}] = 'U';
 
  queue<pair<pair<int, int> , string> > q;
 
  // cout<<s1<<" "<<s2<<endl<<endl;
  q.push({{s1, s2} , ""});
 
  vis[s1][s2]= true ;
 
  while (q.empty() == false)
  {
    auto u = q.front();
    q.pop();
 
    for (auto p : directions)
    {
      int x = p.first + u.first.first;
      int y = p.second + u.first.second;
 
      if (inside(x, y, n, m)  && vis[x][y] ==false && (arr[x][y] == '.' || arr[x][y] == 'B'))
      {
 
        string str = u.second;
        str += hash[{p.first, p.second}];
 
        // cout<<x<<":"<<y<<endl;
        if (arr[x][y] == 'B')
        {
          cout << "YES" << endl;
          cout << str.length() << endl;
          cout << str << endl;
          return;
        }
        // cout << x << ":" << y << endl;
        vis[x][y] = true;
        q.push({{x, y} , str});
      }
    }
  }
 
  cout << "NO" << endl;
}
int main()
{
 
  // freopen("input.txt", "r", stdin);
  // freopen("output.txt", "w", stdout);
 
  ull t = 1;
  // cin >> t;
  // cout << "nooml";
  while (t--)
  {
    solve();
  }
}

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