#include using namespace std; using ll=long long; using pll=pair; using tll=tuple; using ld=long double; const ll INF=(1ll<<60); #define rep(i,n) for(ll i=0;i<(ll)(n);i++) #define all(v) v.begin(),v.end() template void chmin(T &a,T b){ if(a>b){ a=b; } } template void chmax(T &a,T b){ if(a> n; vector a(n); ll cnt=0; rep(i,n){ cin >> a[i]; if(a[i]==1) cnt++; } bool ok=true; rep(i,n-1){ if(a[i]==a[i+1]&&a[i]!=1) ok=false; } if(cnt==n||!ok) cout << "No\n"; else cout << "Yes\n"; } int main(){ ios::sync_with_stdio(false); cin.tie(nullptr); ll t; cin >> t; while(t--){ solve(); } }