import sys
from sys import stdin

CtoI = {}
CtoI["B"] = 0
CtoI["G"] = 1
CtoI["R"] = 2


TT = int(stdin.readline())
ANS = []

for loop in range(TT):

    N = int(stdin.readline())
    DC = {}
    cset = set()

    for i in range(N):

        C,D = stdin.readline()[:-1].split()

        if D not in DC:
            DC[D] = [0,0,0]
            
        DC[D][CtoI[C]] = 1 

        cset.add(C)

    same = [0] * 3

    for D in DC:

        bgr = DC[D]

        if bgr[0] == bgr[1] == 1:
            same[0] = 1
        if bgr[1] == bgr[2] == 1:
            same[1] = 1
        if bgr[2] == bgr[0] == 1:
            same[2] = 1

    #print (cset,same)

    if len(cset) == 1:
        ANS.append("YES")
    elif len(cset) == 2:
        if sum(same) > 0:
            ANS.append("YES")
        else:
            ANS.append("NO")
    else:
        if sum(same) >= 2:
            ANS.append("YES")
        else:
            ANS.append("NO")

print(*ANS, sep="\n")
# print ("\n".join(map(str,ANS)))