#include<bits/stdc++.h>
#define For(i,a,b) for(int i=(a);i<=(b);++i)
#define Rep(i,a,b) for(int i=(a);i>=(b);--i)
using namespace std;
inline int read()
{
	char c=getchar();int x=0;bool f=0;
	for(;!isdigit(c);c=getchar())f^=!(c^45);
	for(;isdigit(c);c=getchar())x=(x<<1)+(x<<3)+(c^48);
	if(f)x=-x;return x;
}

#define fi first
#define se second
#define pb push_back
#define mkp make_pair
typedef pair<int,int>pii;
typedef vector<int>vi;

#define maxn 200005
#define inf 0x3f3f3f3f

int n,m;
char s[2005][2005];
int res[2005][2005],a[2005][2005];
int dx[4]={0,1,0,-1},dy[4]={1,0,-1,0};

void work()
{
	n=read(),m=read();
	For(i,1,n)cin>>(s[i]+1);
	For(i,1,n)For(j,1,m)a[i][j]=(s[i][j]=='B');
	For(i,1,n)
		For(j,1,m){
			res[i][j]=2;
			For(k,0,3){
				int xx=i+dx[k],yy=j+dy[k];
				if(xx>0&&yy>0&&xx<=n&&yy<=m)a[xx][yy]^=1;
			}
		}
	For(i,1,n)
		For(j,1,m)if(a[i][j])res[i][j]^=1;
	puts("1")
;	For(i,1,n){
		For(j,1,m)cout<<res[i][j];
		puts("");
	}
}

signed main()
{
	int T=1;
	while(T--)work();
	return 0;
}