uva 11520

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<algorithm>

using namespace std;

#define MAXN (10+5)

char read[MAXN][MAXN];

int main(){
int T;
scanf("%d", &T);
int t = 0;

while(T--){
int n;
scanf("%d", &n);
for(int i = 0; i < n; i++) scanf("%s", read[i]);

for(int i = 0; i < n; i++)
for(int j = 0; j < n; j++)
if(read[i][j] == '.'){
for(char ch = 'A'; ch <= 'Z'; ch++){
bool ok = true;

if(i>0 && read[i-1][j] == ch) ok = false;
if(i<n-1 && read[i+1][j] == ch) ok = false;
if(j>0 && read[i][j-1] == ch) ok = false;
if(j<n-1 && read[i][j+1] == ch) ok = false;

if(ok){
read[i][j] = ch;
break;
}
}
}

printf("Case %d:\n", ++t);
for(int i = 0; i < n; i++) printf("%s\n", read[i]);
}

return 0;
}