#include <iostream>
#include <vector>
using namespace std;

int main() {
    int T;
    cin >> T;
    while(T--) {
        int N;
        cin >> N;
        vector<int> arr(N);
        for(int i = 0; i < N; i++) {
            cin >> arr[i];
        }
        int maxLen = 0;
        int len = 0;
        for(int i = 0; i < N; i++) {
            if(arr[i] == 1) {
                len = 1;
            } else if(arr[i] == 2) {
                len = 0;
            } else if(arr[i] == 3 && len > 0) {
                len++;
                maxLen = max(maxLen, len);
            } else if(len > 0) {
                len++;
            }
        }
        cout << maxLen << endl;
    }
    return 0;
}