graph

import java.util.Scanner;
import java.util.ArrayList;
/**
 *
 * @author henrico
 * problem 459
 */
public class Main {
    private static ArrayList<Integer>[] graph;
    private static boolean[] visited;
    private static int count;

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        sc.nextLine();
        for(int i = 0;i<n;i++){
            int max = sc.next().charAt(0) - 'A' +1 ;
            graph = new ArrayList[max];
            visited = new boolean[max];
            for(int j = 0; j<max;j++){
                graph[j] = new ArrayList<Integer>();
            }
            sc.nextLine();
            String tmp = sc.nextLine();
            while(!tmp.equals("")){
                int x = tmp.charAt(0)-'A';
                int y = tmp.charAt(1)-'A';
                graph[x].add(y);
                graph[y].add(x);
                tmp = sc.nextLine();
            }
            count = 0;
            for(int j=0;j<max;j++){
                if(!visited[j]){
                    count++;
                    dfs(j);
                }
            }
            System.out.println(count);
            System.out.println();
        }
    }

    private static void dfs(int idx){
        visited[idx]=true;
        for(int i = 0; i<graph[idx].size();i++){
            if(!visited[graph[idx].get(i)]){
                dfs(graph[idx].get(i));
            }
        }
    }
}