import sys
from sys import stdin

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

for loop in range(TT):

    N = int(stdin.readline())
    DC = []

    for i in range(N):

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

    DC.sort()

    cset = set()
    for i in range(N):
        cset.add(DC[i][1])

    same = [0] * 3

    for i in range(N-1):

        d1,c1 = DC[i]
        d2,c2 = DC[i+1]

        if d1 == d2:

            cs = (c1,c2)

            if "B" in cs and "G" in cs:
                same[0] = 1
            if "G" in cs and "R" in cs:
                same[1] = 1
            if "R" in cs and "B" in cs:
                same[2] = 1


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

print ("\n".join(ANS))