#include<bits/stdc++.h>
using namespace std;
#define nl "\n"
#define fi first
#define se second
#define pb push_back
#define ll long long
#define ull unsigned ll
#define RV  return void
// #define inf 2000000000
#define sz(x) int(x.size())
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define Mini(x) *min_element(all(x))
#define Maxi(x) *max_element(all(x))
#define fixed(n) fixed << setprecision(n)
#define ceil(w, m) (((w) / (m)) + ((w) % (m) ? 1 : 0))
#define cin(v) for (auto&i:v) cin >> i;
#define cout(v) for (auto&i:v) cout << i << " ";
#define clr(memo, x) memset(memo, x, sizeof memo)
#define updmin(a, b) a = min(a, b)
#define updmax(a, b) a = max(a, b)
#define vi vector < int >
#define vl vector < ll >
#define vc vector < char >
#define vs vector < string >
#define v2i vector < vector < int > >
#define v2l vector < vector < int > >
#define seti set < int >
#define setl set < ll >
#define mapii map < int , int >
#define mapll map < ll , ll >
#define mapli map < ll , int >
#define mapci map < char , int >
#define mapsi map < string , int >
#define pll pair < ll , ll >
#define pii pair < int , int >
#define range(l,r,x) for(int i=l ; i < r ; i+=x)
#define FastCode ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
vector < string > ternary= {"NO\n" , "YES\n"};

void  Zainab(){
            #ifndef ONLINE_JUDGE
              freopen("input.txt", "r", stdin);
              freopen("output.txt", "w", stdout);
            #endif
}


/*================================  solution  ================================ */


const ll N = 1e3 + 5 , inf = 1e18;



int n , m , X1 , X2 , Y1 , Y2 ;

char arr[N][N];


int dx[]={ -1 , 1 ,  0 , 0 };
int dy[]={  0 , 0 ,  1 , -1};
char C[] ={ 'U' , 'D' , 'R' , 'L' };

bool valid(int x , int y){
    return x >=0 and y>=0 and x < n and y < m ;
}


ll dp[N+10][N+10];



ll rec(int x , int y ){

    if(x==X2 and y==Y2) return 0 ;
    if(!valid(x,y) or arr[x][y]=='#') return inf ;

    ll& ret = dp[x][y];
    if(~ret) return ret;

    ret = inf;
    for(int i =0 ; i < 4 ; i++){
        int newX = x + dx[i] , newY = y + dy[i];
        if(valid(newX , newY) and arr[newX][newY]!='#')
            ret = min(ret , 1+ rec(newX , newY));
    }
    return ret ;
}


void build(int x , int y ){

        if(x==X2 and y==Y2) return ;
        if(!valid(x,y) or arr[x][y]=='#') return ;

        ll ret = inf;
        for(int i =0 ; i < 4 ; i++){
            int newX = x + dx[i] , newY = y + dy[i];
            if(valid(newX , newY) and arr[newX][newY]!='#')
               ret = min(ret , 1 +rec(newX , newY));
        }

        for(int i =0 ; i < 4 ; i++){
            int newX = x + dx[i] , newY = y + dy[i];
            if(valid(newX , newY) and arr[newX][newY]!='#' and ret == 1 + rec(newX , newY)){
                cout << C[i];
                build(newX , newY);
                return ;
            }
        }
}


void myCode(){

cin >> n >> m ;

for(int i =0 ; i < n ; i++){
    for(int j =0 ; j < m ; j++){
        cin >> arr[i][j];
        if(arr[i][j]=='A') X1=i , Y1=j;
        else if(arr[i][j]=='B') X2 = i , Y2 = j;
    }
}

clr(dp , -1);



ll ans = inf ;

ans = min(ans , rec(X1 , Y1));

if(ans == inf) RV(cout << "NO");


cout << "YES\n" << ans << nl;

build(X1,Y1);



}


int main(){
                                   FastCode ;
                                   Zainab() ;





        int testCase=1;
            //  cin >> testCase ;
        for(int i=1 ; i<= testCase ; i++){
            myCode();
        }


    return 0;
}