def solve():
    n = int(input())
    a = list(filter(lambda x: x != 1, map(int, input().split())))
    if not a or len(a) % 2:
        return False
    return a == [a[0], 2 - a[0]] * (len(a) // 2)

for _ in range(int(input())):
    print('Yes' if solve() else 'No')