#include <bits/stdc++.h>
using namespace std;
int main(){
  int T;
  cin >> T;
  for (int i = 0; i < T; i++){
    int N;
    cin >> N;
    vector<int> A(N);
    for (int j = 0; j < N; j++){
      cin >> A[j];
    }
    vector<int> B;
    for (int j = 0; j < N; j++){
      if (A[j] != 1){
        B.push_back(A[j]);
      }
    }
    if (B.empty()){
      cout << "No" << endl;
    } else if (B.size() % 2 == 1){
      cout << "No" << endl;
    } else {
      int cnt = B.size();
      bool ok = true;
      for (int j = 0; j < cnt - 1; j++){
        if (B[j] == B[j + 1]){
          ok = false;
        }
      }
      if (ok){
        cout << "Yes" << endl;
      } else {
        cout << "No" << endl;
      }
    }
  }
}