#include #include // url #define rep(i,a,b) for(int i=a;i=a;i--) #define all(x) (x).begin(),(x).end() #define pb(x) push_back(x); templatebool chmax(T &a, const T &b) { if (abool chmin(T &a, const T &b) { if (b; const ll mod=998244353; // using mint = static_modint<1000000007>; //const ll mod=1e9+7; int dx[4]={1,0,-1,0}; int dy[4]={0,1,0,-1}; const string zton="0123456789"; const string atoz="abcdefghijklmnopqrstuvwxyz"; const string ATOZ="ABCDEFGHIJKLMNOPQRSTUVWXYZ"; const ll inf=(1ll<<60); // const int inf=(1<<30); lld dist(lld x1,lld x2,lld y1,lld y2){ lld res=(x1-x2)*(x1-x2)+(y1-y2)*(y1-y2); res=sqrt(abs(res)); return res; } lld arg(lld x,lld y){ const lld eps=1e-8; lld res=0; if(abs(x)+abs(y)<=eps)return 0.0; else if(abs(x)<=eps){ if(y>=0.0)return (M_PI/2); else return (M_PI/2+M_PI); } else if(abs(y)<=eps){ if(x>=0.0)return 0.0; else return M_PI; } res=atan2(abs(y),abs(x)); if(x<=0&&y>=0)res=(M_PI-res); else if(x<=0&&y<=0)res+=(M_PI); else if(x>=0&&y<=0)res=(M_PI*2-res); return res; } ll gcd(ll a,ll b){ if(a==0||b==0)return a+b; ll r; r=a%b; if(r==0){ return b; } else{ return gcd(b,r); } } std::ostream &operator<<(std::ostream &dest, __int128_t value) { std::ostream::sentry s(dest); if (s) { __uint128_t tmp = value < 0 ? -value : value; char buffer[128]; char *d = std::end(buffer); do { --d; *d = "0123456789"[tmp % 10]; tmp /= 10; } while (tmp != 0); if (value < 0) { --d; *d = '-'; } int len = std::end(buffer) - d; if (dest.rdbuf()->sputn(d, len) != len) { dest.setstate(std::ios_base::badbit); } } return dest; } __int128 parse128(string &s) { __int128 ret = 0; for (int i = 0; i < s.length(); i++){ if ('0' <= s[i] && s[i] <= '9'){ ret = 10 * ret + s[i] - '0'; } } return ret; } using l3 = __int128; bool comp_arg(pair a,pair b){ if(a.second>=0&&b.second<0)return true; else if(a.second<0&&b.second>=0)return false; if(a.second>=0&&b.second>=0){ if(a.first>=0&&b.first<0)return true; } else{ if(a.first>=0&&b.first<0)return false; } ll det=a.first*b.second-a.second*b.first; if(det>0)return true; return false; } bool solve(int N,vector &A){ vector v; rep(i,0,N){ if(A[i]==0){ v.pb(i); } else if(A[i]==2){ v.pb(i); } } if(v.size()==0||v.size()%2==1)return false; rep(i,0,v.size()){ int ni=(i+1)%v.size(); int l=v[i]; int r=v[ni]; if(A[l]==A[r])return false; } rep(i,0,N){ int l=(N+i-1)%N; int r=(i+1)%N; if(A[i]==0){ if(A[l]==0||A[r]==0)return false; } else if(A[i]==2){ if(A[l]==2||A[r]==2)return false; } else{ if(A[l]==1||A[r]==1)continue; if(A[l]==A[r])return false; } } return true; } int main(void){ ios::sync_with_stdio(false); cin.tie(nullptr); int t;cin >> t; vector ans; rep(i,0,t){ int N;cin >> N; vector A(N); rep(j,0,N){ cin >> A[j]; } ans.pb(solve(N,A)); } rep(i,0,t){ if(ans[i]){ cout << "Yes" << endl; } else{ cout << "No" << endl; } } }