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;
}