import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.LinkedList;

public class ccc18s3 {

	public static void main(String[] args) throws IOException{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] a = br.readLine().split(" ");
		int R = Integer.parseInt(a[0]);
		int C = Integer.parseInt(a[1]);
		char[][] map = new char[R][C];
		int[][] step = new int[R][C];
		for(int r = 0; r < R; r++){
			map[r] = br.readLine().toCharArray();
			Arrays.fill(step[r], Integer.MAX_VALUE);
		}
		LinkedList<Integer> rq = new LinkedList<>();
		LinkedList<Integer> cq = new LinkedList<>();
		Rrepeat:
		for(int r = 0; r < R; r++){
			for(int c = 0; c < C; c++){
				if(map[r][c] == 'S'){
					step[r][c] = 0;
					rq.add(r);
					cq.add(c);
					break Rrepeat;
				}
			}
		}
		while(!rq.isEmpty()){
			int r = rq.poll();
			int c = cq.poll();
			char currChar = map[r][c];
			int currInt = step[r][c] + 1;
			if(currChar == '.' || currChar == 'S'){
				if(step[r - 1][c] > currInt){
					step[r - 1][c] = currInt;
					rq.add(r - 1);
					cq.add(c);
				}
				if(step[r + 1][c] > currInt){
					step[r + 1][c] = currInt;
					rq.add(r + 1);
					cq.add(c);
				}
				if(step[r][c - 1] > currInt){
					step[r][c - 1] = currInt;
					rq.add(r);
					cq.add(c - 1);
				}
				if(step[r][c + 1] > currInt){
					step[r][c + 1] = currInt;
					rq.add(r);
					cq.add(c + 1);
				}
			}
			if(currChar == 'L'){
				if(step[r][c - 1] > currInt){
					step[r][c - 1] = currInt;
					rq.add(r);
					cq.add(c - 1);
				}
			}
			if(currChar == 'R'){
				if(step[r][c + 1] > currInt){
					step[r][c + 1] = currInt;
					rq.add(r);
					cq.add(c + 1);
				}
			}
			if(currChar == 'U'){
				if(step[r - 1][c] > currInt){
					step[r - 1][c] = currInt;
					rq.add(r - 1);
					cq.add(c);
				}
			}
			if(currChar == 'D'){
				if(step[r + 1][c] > currInt){
					step[r + 1][c] = currInt;
					rq.add(r + 1);
					cq.add(c);
				}
			}
		}
		for(int r = 0; r < R; r++){
			for(int c = 0; c < C; c++){
				if(map[r][c] == '.'){
					if(step[r][c] == Integer.MAX_VALUE) System.out.println(-1);
					else System.out.println(step[r][c]);
				}
			}
		}
		br.close();
	}

}