#include <iostream>
#include <vector>
#include <string>

using namespace std;


int whoWins( vector<string> map, int whoseOn , int x, int y,int height)
{
	int width;
	width = map[0].length();
	bool target = false;
	map[x][y] = 'X';
	for ( int i = -1; i < 2; i++ )
		for ( int j = -1; j < 2; j++ )
		{
			if ( ( i == j ) || ( i == -j ) )
				continue;
			if ( ( x+i < 0 ) || ( y + j < 0 ) || ( x + i >= height ) || ( y + j >= width ) )
				continue;
			if ( map[x+i][y+j] == 'X' )
				continue;
			int decision = whoWins( map, 1-whoseOn, x+i, y+j , height);
			if ( decision == whoseOn )
			{
				target = true;
				break;
			}
		}
	if ( target )
		return whoseOn;
	return 1-whoseOn;
}

int main()
{
	int width, heigth;
	cin >> heigth >> width;
	while ( ( width != 0 ) || ( heigth != 0 ) )
	{
		vector<string> situation;
		for ( int i = 0; i < heigth; i++ )
		{
			string s;
			cin >> s;
			situation.push_back(s);
		}
		for ( int i = 0; i < heigth; i++ )
		{
			for ( int j = 0; j < width; j++ )
			{
				if ( situation[i][j] == 'X' )
				{
					cout << 'X';
					continue;
				}
				int decision = whoWins( situation, 0,i,j,heigth);
				if ( decision == 0 )
					cout << "A";
				else
					cout << "B";
			}
			cout << endl;
		}
		cout << endl;
		cin >> heigth >> width;
	}
	return 0;
}