T=int(input())
for _ in range(T):
  N=int(input())
  A=list(map(int, input().split()))
  f=1 
  if A.count(0)==0 or A.count(2)==0 or sum(A)!=N:
    f=0 
  for i in range(N):
    if A[i-1]==A[i] and A[i]!=1:
      f=0 
  if f==1:
    print('Yes')
  else:
    print('No')