import sys
from collections import deque, Counter
sys.setrecursionlimit(5 * 10 ** 5)
from pypyjit import set_param
set_param('max_unroll_recursion=-1')
input = lambda: sys.stdin.readline().rstrip()
ii = lambda: int(input())
mi = lambda: map(int, input().split())
li = lambda: list(mi())
inf = 2 ** 63 - 1
mod = 998244353

import itertools


def solve():
    n = ii()
    CD = [list(input().split()) for _ in range(n)]
    D = {}
    D['R'] = set()
    D['G'] = set()
    D['B'] = set()
    for i in range(n):
        c, d = CD[i]
        D[c].add(d)
    ans = 'NO'
    for v in itertools.permutations('RGB'):
        if (D[v[0]] & D[v[1]] and (D[v[1]] & D[v[2]] or (not D[v[2]])) or D[v[0]] and not D[v[1]] and not D[v[2]]):
            ans = 'YES'
    print(ans)

for _ in range(ii()):
    solve()