#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <limits.h>
#include <math.h>
#include <time.h>
#include <iostream>
#include <functional>
#include <numeric>
#include <algorithm>
#include <stack>
#include <queue>
#include <deque>
#include <vector>
#include <string>
#include <bitset>
#include <map>
#include <set>
using namespace std;
typedef long long lint;
typedef long double llf;
typedef pair<int, int> pi;
char str[30][100], ret[30][100];
int r, c, dp[13][41][1<<12][2];
int f(int x, int y, int bit, int lef){
if(y == c / 2) return 0;
if(x == r / 2){
if(lef) return 1e9;
return dp[x][y][bit][lef] = f(0, y+1, bit, 0);
}
if(~dp[x][y][bit][lef]) return dp[x][y][bit][lef];
int ret = 1e9;
if(str[2*x+1][2*y+1] == 'X'){
if(lef && (bit >> x) % 2 == 0){
ret = min(ret, f(x+1, y, bit, 0) + 2);
}
if(!lef && str[2*x+2][2*y+1] == ' ' && (bit >> x) % 2 == 0){
ret = min(ret, f(x+1, y, bit, 1));
}
if(!lef && (bit >> x) % 2 == 1){
ret = min(ret, f(x+1, y, bit ^ (1<<x), 0) + 2);
}
if(!lef && str[2*x+1][2*y+2] == ' ' && (bit >> x) % 2 == 0){
ret = min(ret, f(x+1, y, bit ^ (1<<x), 0));
}
}
else{
if(!lef && (bit >> x) % 2 == 0){
ret = min(ret, f(x+1, y, bit, 0));
}
if(lef && (bit >> x) % 2 == 1){
ret = min(ret, f(x+1, y, bit ^ (1<<x), 0) + 4);
}
if(!lef && (bit >> x) % 2 == 1 && str[2*x+1][2*y+2] == ' '){
ret = min(ret, f(x+1, y, bit, 0) + 2);
}
if(lef && (bit >> x) % 2 == 0 && str[2*x+1][2*y+2] == ' '){
ret = min(ret, f(x+1, y, bit ^ (1<<x), 0) + 2);
}
if(lef && (bit >> x) % 2 == 0 && str[2*x+2][2*y+1] == ' '){
ret = min(ret, f(x+1, y, bit, 1) + 2);
}
if(!lef && (bit >> x) % 2 == 0 && str[2*x+1][2*y+2] == ' ' && str[2*x+2][2*y+1] == ' '){
ret = min(ret, f(x+1, y, bit ^ (1<<x), 1));
}
if(!lef && (bit >> x) % 2 == 1 && str[2*x+2][2*y+1] == ' '){
ret = min(ret, f(x+1, y, bit ^ (1<<x), 1) + 2);
}
}
return dp[x][y][bit][lef] = ret;
}
void track(int x, int y, int bit, int lef){
if(y == c / 2) return;
if(x == r / 2){
track(0, y+1, bit, 0);
return;
}
if(str[2*x+1][2*y+1] == 'X'){
if(lef && (bit >> x) % 2 == 0 && f(x, y, bit, lef) == f(x+1, y, bit, 0) + 2){
track(x+1, y, bit, 0);
}
else if(!lef && str[2*x+2][2*y+1] == ' ' && (bit >> x) % 2 == 0 && f(x, y, bit, lef) == f(x+1, y, bit, 1)){
str[2*x+2][2*y+1] = '.';
track(x+1, y, bit, 1);
}
else if(!lef && (bit >> x) % 2 == 1 && f(x, y, bit, lef) == f(x+1, y, bit ^ (1<<x), 0) + 2){
track(x+1, y, bit ^ (1<<x), 0);
}
else if(!lef && str[2*x+1][2*y+2] == ' ' && (bit >> x) % 2 == 0 && f(x, y, bit, lef) == f(x+1, y, bit ^ (1<<x), 0)){
str[2*x+1][2*y+2] = '.';
track(x+1, y, bit ^ (1<<x), 0);
}
else{
assert(0);
}
}
else{
if(!lef && (bit >> x) % 2 == 0 && f(x, y, bit, lef) == f(x+1, y, bit, 0)){
track(x+1, y, bit, 0);
}
else if(lef && (bit >> x) % 2 == 1 && f(x, y, bit, lef) == f(x+1, y, bit ^ (1<<x), 0) + 4){
str[2*x+1][2*y+1] = '.';
track(x+1, y, bit ^ (1<<x), 0);
}
else if(!lef && (bit >> x) % 2 == 1 && str[2*x+1][2*y+2] == ' ' && f(x, y, bit, lef) == f(x+1, y, bit, 0) + 2){
str[2*x+1][2*y+1] = '.';
str[2*x+1][2*y+2] = '.';
track(x+1, y, bit, 0);
}
else if(lef && (bit >> x) % 2 == 0 && str[2*x+1][2*y+2] == ' ' && f(x, y, bit, lef) == f(x+1, y, bit ^ (1<<x), 0) + 2){
str[2*x+1][2*y+2] = '.';
str[2*x+1][2*y+1] = '.';
track(x+1, y, bit ^ (1<<x), 0);
}
else if(lef && (bit >> x) % 2 == 0 && str[2*x+2][2*y+1] == ' ' && f(x, y, bit, lef) == f(x+1, y, bit, 1) + 2){
str[2*x+2][2*y+1] = '.';
str[2*x+1][2*y+1] = '.';
track(x+1, y, bit, 1);
}
else if(!lef && (bit >> x) % 2 == 0 && str[2*x+1][2*y+2] == ' ' && str[2*x+2][2*y+1] == ' ' && f(x, y, bit, lef) == f(x+1, y, bit ^ (1<<x), 1)){
str[2*x+2][2*y+1] = '.';
str[2*x+1][2*y+2] = '.';
str[2*x+1][2*y+1] = '.';
track(x+1, y, bit ^ (1<<x), 1);
}
else if(!lef && (bit >> x) % 2 == 1 && str[2*x+2][2*y+1] == ' ' && f(x, y, bit, lef) == f(x+1, y, bit ^ (1<<x), 1) + 2){
str[2*x+2][2*y+1] = '.';
str[2*x+1][2*y+1] = '.';
track(x+1, y, bit ^ (1<<x), 1);
}
else{
assert(0);
}
}
}
int main(){
memset(dp, -1, sizeof(dp));
scanf("%d %d\n",&r,&c);
for(int i=0; i<r; i++){
fgets(str[i], 88, stdin);
}
cout << f(0, 0, 0, 0) << endl;
track(0, 0, 0, 0);
for(int i=0; i<r; i++) cout << str[i];
}
