import sys
input = sys.stdin.readline
from collections import *

def f(c):
    if c=='R':
        return 0
    elif c=='G':
        return 1
    else:
        return 2

def solve():
    N = int(input())
    S = [set() for _ in range(3)]
    
    for i in range(N):
        C, D = input().split()
        S[f(C)].add(D)
    
    v, e = 0, 0
    
    for i in range(3):
        if len(S[i])>0:
            v += 1
    
        for j in range(i+1, 3):
            if len(S[i]&S[j])>0:
                e += 1
    
    if e>=v-1:
        print('YES')
    else:
        print('NO')

for _ in range(int(input())):
    solve()