import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.NoSuchElementException;

public class Main {
	public static void main(String args[]) {
		FastScanner scanner = new FastScanner();
		w=scanner.nextInt();
		h=scanner.nextInt();
		bord=new char[h][w];
		tarX1=new ArrayList<>();
		tarY1=new ArrayList<>();
		tarX2=new ArrayList<>();
		tarY2=new ArrayList<>();
		for(int i=0;i<h;i++) {
			String s=scanner.next();
			for(int j=0;j<w;j++) {
				char c=s.charAt(j);
				bord[i][j]=c;
			}
		}
		out:for(int i=0;i<h;i++) {
			for(int j=0;j<w;j++) {
				if(bord[i][j]=='.') {
					dfs1(i,j);

					break out;
				}
			}
		}
		out:for(int i=0;i<h;i++) {
			for(int j=0;j<w;j++) {
				if(bord[i][j]=='.'&&check(j,i,tarX1,tarY1)) {
					dfs2(i,j);
					break out;
				}
			}
		}
		
		int min=Integer.MAX_VALUE;
		for(int i=0;i<tarX1.size();i++) {
			for(int j=0;j<tarX2.size();j++) {
				int tmp=Math.abs(tarX1.get(i)-tarX2.get(j))+Math.abs(tarY1.get(i)-tarY2.get(j));
				tmp--;
				min=Math.min(tmp, min);
			}
		}
		System.out.println(min);
	}

	static int h;
	static int w;
	static char[][] bord;
	static List<Integer> tarX1;
	static List<Integer> tarY1;
	static List<Integer> tarX2;
	static List<Integer> tarY2;
	
	private static void dfs1(int i, int j) {
		tarX1.add(j);
		tarY1.add(i);
		check4Neighborhood1(j,i);
	}
	
	private static void check4Neighborhood1(int x, int y) {
		for (int i = -1; i <= 1; i++) {
			for (int j = -1; j <= 1; j++) {
				if ((i == 0 && j != 0) || (i != 0 && j == 0)) {
					int tarX = j + x;
					int tarY = i + y;
					if (0 <= tarX && tarX <= bord[0].length - 1 && 0 <= tarY && tarY <= bord.length - 1) {
						if (bord[tarY][tarX]=='.'&&check(tarX,tarY,tarX1,tarY1)) {
							dfs1(tarY,tarX);
						}
					}
				}
			}
		}
	}
	
	private static boolean check(int tarX, int tarY, List<Integer> tarX12, List<Integer> tarY12) {
		for(int i=0;i<tarX12.size();i++) {
			if(tarX==tarX12.get(i)&&tarY==tarY12.get(i)) {
				return false;
			}
		}
		return true;
	}

	private static void dfs2(int i, int j) {
		tarX2.add(j);
		tarY2.add(i);
		check4Neighborhood2(j,i);
	}
	
	private static void check4Neighborhood2(int x, int y) {
		for (int i = -1; i <= 1; i++) {
			for (int j = -1; j <= 1; j++) {
				if ((i == 0 && j != 0) || (i != 0 && j == 0)) {
					int tarX = j + x;
					int tarY = i + y;
					if (0 <= tarX && tarX <= bord[0].length - 1 && 0 <= tarY && tarY <= bord.length - 1) {
						if (bord[tarY][tarX]=='.'&&check(tarX,tarY,tarX2,tarY2)) {
							dfs2(tarY,tarX);
						}
					}
				}
			}
		}
	}

}




class FastScanner {
    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;
    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        }else{
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }
    private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;}
    private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
    public boolean hasNext() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; return hasNextByte();}
    public String next() {
        if (!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while(isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    public long nextLong() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true){
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            }else if(b == -1 || !isPrintableChar(b)){
                return minus ? -n : n;
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
    public int nextInt() {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException();
        return (int) nl;
    }
    public double nextDouble() { return Double.parseDouble(next());}
}