#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include <iostream>

int qk=0,qb=0;

char data[501][501];
void banjir(int arah,int a,int b,int maxa,int maxb,char x){
    if(data[a][b]=='.'){
        data[a][b]=x;
        if(x=='K')qk++;else qb++;
        if(arah!=1)if(a-1>=0)banjir(3,a-1,b,maxa,maxb,x);
        if(arah!=2)if(b+1<=maxb)banjir(4,a,b+1,maxa,maxb,x);
        if(arah!=3)if(a+1<=maxa)banjir(1,a+1,b,maxa,maxb,x);
        if(arah!=4)if(b-1>=0)banjir(2,a,b-1,maxa,maxb,x);
    }
}

int main()
{
        int a,b;
        int ak,bk,ab,bb;
        scanf("%i %i",&a,&b);
        //for(int q=0;q<80;q++)for(int p=0;p<80;p++)data[q][p]='x';

        for(int q=0;q<a;q++){
            std::cin.getline(data[q],b+1);
        }


        for(int q=0;q<a;q++)for(int p=0;p<b;p++)
            if(data[q][p]=='K'){
                ak=q;
                bk=p;
            }else if(data[q][p]=='B'){
                ab=q;
                bb=p;
            }

        banjir(1,ak+1,bk,a-1,b-1,'K');
        banjir(2,ak,bk-1,a-1,b-1,'K');
        banjir(3,ak-1,bk,a-1,b-1,'K');
        banjir(4,ak,bk+1,a-1,b-1,'K');

        banjir(1,ab+1,bb,a-1,b-1,'B');
        banjir(2,ab,bb-1,a-1,b-1,'B');
        banjir(3,ab-1,bb,a-1,b-1,'B');
        banjir(4,ab,bb+1,a-1,b-1,'B');

        for(int q=0;q<a;q++)printf("%s\n",data[q]);
        /*
        if(qk==qb){
            printf("SERI\n");
        }else if(qk>qb){
            printf("K %i\n",qk-qb);
        }else{
            printf("B %i\n",qb-qk);
        }*/


}