[20:22:29] We.Pepsi.Infi: #include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <string>
#include <string.h>
#include <map>
#include <set>
#include <vector>
#include <memory.h>
#include <math.h>
#include <queue>
#include <stack>
#include <algorithm>

#define INF (10000000)
#define PI (acos(-1))
#define EPS (1e-8)

#define pb push_back
#define mp make_pair
#define li long long

using namespace std;
struct Point{
    int x;
    int y;
};
int n,m;
char g[1502][1502];
bool mark[1502][1502];
int dx[4] = { 1, 0, -1, 0 };
int dy[4] = { 0, 1, 0, -1 };
int dist[1502][1502];
queue<Point> q;
int parent[1502 * 1502];
int rank[1502*1502];
Point a, b;
void make_set (int v) {
 parent[v] = v;
 rank[v] = 0;
}

int find_set (int v) {
 if (v == parent[v])
  return v;
 return parent[v] = find_set (parent[v]);
}
void union_sets (int a, int b) {
 a = find_set (a);
 b = find_set (b);
 if (a != b) {
  if (rank[a] < rank[b])
   swap (a, b);
  parent[b] = a;
  if (rank[a] == rank[b])
   ++rank[a];
 }
}
void dfs(Point v) {
  mark[v.x][v.y] = true;
  if (g[v.x][v.y] == '.' || g[v.x][v.y] == 'L')
  for (int i = 0; i < 4; ++i) {
   if ((g[v.x + dx[i]][v.y + dy[i]] == '.' || g[v.x + dx[i]][v.y + dy[i]] == 'L') && !mark[v.x + dx[i]][v.y + dy[i]]) {
    union_sets((v.x - 1) * m + v.y, (v.x - 1 + dx[i]) * m + v.y + dy[i]);
    Point cur;
    cur.x = v.x + dx[i];
    cur.y = v.y + dy[i];
    dfs(cur);
   }
  }
 }
void d(){
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++)
            dist[i][j] = 10000000;
    queue<Point> w;
    while (!q.empty()){
        Point cur = q.front();
        w.push(cur);
        dist[cur.x][cur.y] = 1;
        q.pop();
    }
 while (w.size() > 0){
        Point tmp = w.front();
        w.pop();
        for (int i = 0; i < 4; ++i) {
    if (g[tmp.x + dx[i]][tmp.y + dy[i]] == 'X' && dist[tmp.x + dx[i]][tmp.y + dy[i]] > dist[tmp.x][tmp.y]){
                    Point get;
                    get.x = tmp.x + dx[i];
                    get.y = tmp.y + dy[i];
                    w.push(get);
                    dist[tmp.x + dx[i]][tmp.y + dy[i]] = dist[tmp.x][tmp.y] + 1;
    }
    }
 }
    for (int i = 1; i <= n; ++i) {
   for (int j = 1; j <= m; ++j)
    if (dist[i][j] == 10000000)
     dist[i][j] = 0;
    }
}
bool used[1502][1502];
void bfs() {
  int cnt = 1;
  Point lol = q.front();
  used[lol.x][lol.y] = true;
  while (!q.empty()) {
   if (find_set((a.x - 1) * m + a.y) == find_set((b.x - 1) * m + b.y)) {
    cout << cnt;
    return;
   }
   Point tmp = q.front();
   q.pop();
   if (dist[tmp.x][tmp.y] > cnt) {
    cnt++;
   }
   for (int i = 0; i < 4; ++i) {
    if (dist[tmp.x + dx[i]][tmp.y + dy[i]] == dist[tmp.x][tmp.y] + 1 && !used[tmp.x + dx[i]][tmp.y + dy[i]]) {
     Point cur;
     cur.x = tmp.x + dx[i];
     cur.y = tmp.y + dy[i];
     q.push(cur);
     used[tmp.x + dx[i]][tmp.y + dy[i]] = true;
    }
    if (g[tmp.x + dx[i]][tmp.y + dy[i]] == '.' || g[tmp.x + dx[i]][tmp.y + dy[i]] == 'L') {
     union_sets((tmp.x + dx[i] - 1) * m + tmp.y + dy[i], (tmp.x - 1) * m + tmp.y);
     used[tmp.x][tmp.y] = true;
     g[tmp.x][tmp.y] = '.';
    }
   }
  }
}
int main()
{
 freopen("input.txt","r",stdin);
 freopen("output.txt","w",stdout);
 cin >> n >> m;
 for (int i = 0; i <= n + 1; i++)
        for (int j = 0; j <= m  + 1; j++)
            g[i][j] = ' ';
    int cnt = 0;
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++){
            cin >> g[i][j];
            if (g[i][j] == 'L')
                if (cnt == 0){
                    a.x = i;
                    a.y = j;
                    cnt++;
                }
                else{
                    b.x = i;
                    b.y = j;
                }
        }
    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= m; j++){
            for (int k = 0; k < 4; k++)
                if ((g[i + dx[k]][j + dy[k]] == '.' || g[i + dx[k]][j + dy[k]] == 'L') && !mark[i + dx[k]][j + dy[k]] && g[i][j] == 'X') {
      mark[i][j] = true;
      Point cur;
      cur.x = i;
      cur.y = j;
      q.push(cur);
                }
        }
    }
    d();
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++)
            mark[i][j] = false;
    for (int i = 1; i <= n; ++i)
   for (int j = 1; j <= m; ++j)
    make_set((i - 1) * m + j);
 for (int i = 1; i <= n; ++i) {
   for (int j = 1; j <= m; ++j) {
    if (!mark[i][j]) {
        Point cur;
        cur.x = i;
        cur.y = j;
     dfs(cur);
    }
   }
    }
    if (find_set((a.x - 1) * m + a.y) == find_set((b.x - 1) * m + b.y)) {
   cout << 0;
   return 0;
  }
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++)
            if (dist[i][j] == 1){
                Point get;
                get.x = i;
                get.y = j;
                q.push(get);
            }
    bfs();
}