#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <utility>
#include <cassert>
#include <stdio.h>
using namespace std;
#define fi(m,n) for(unsigned i=m ; i < n ;++i)
#define fin cin
//ifstream fin("a.in");
unsigned v[10001]={0};
int main()
{
	int t;
	fin>>t;
	char line[1002]={0};
	while(t--)
	{
		int n;
		unsigned ma=0,mi=10000,x,y;
		//vector<unsigned> v(1001,0);
		
		char c;
		fin>>n;
		while(n--)
		{
			fin>>c>>x>>y;
			fi(x,y)
				++v[i];
		}
		fi(0,1000)
			if(v[i]!=64)
				//cout<<(char)('A'+v[i]-1);
			{
				line[ma++]=v[i];
				v[i]=64;
			}
		line[ma]=0;
		puts(line);
				
	}

}