from sys import stdin
input = stdin.readline

for _ in range(int(input())):
    N = int(input())
    S = input().rstrip("\n")

    for i in range(N):
        if S[i] == "?":
            if S[(i-1)%N] != "?" and S[(i+1)%N] != "?" and S[(i-1)%N] == S[(i-2)%N] and S[(i+1)%N] == S[(i+2)%N] and S[(i-1)%N] != S[(i+1)%N]:
                print("No")
                break
        else:
            if S[i] == S[(i+1)%N] == S[(i+2)%N]:
                print("No")
                break
    else:
        print("Yes")