#include<iostream>#include<string>#include<vector>#include<algorithm>#include<set>using namespace std;namespace{bool cmp(const string &s1, const string &s2){return s1.size() < s2.size();}void put(const string &s, set<string> &S){for (size_t i = 0; i < s.size(); i++)for (size_t len = 1; len + i <= s.size(); len++)S.insert(s.substr(i, len));}}int main(){int t;cin >> t;vector<string> V;set<string> S;while (t--){int n;cin >> n;V.clear();string s;for (int i = 0; i < n; i++){cin >> s;V.push_back(s);}sort(V.begin(), V.end(), cmp);S.clear();put(V[0], S);reverse(V[0].begin(), V[0].end());put(V[0], S);size_t max = 0;for (set<string>::iterator it = S.begin(); it != S.end(); it++){bool find = true;for (size_t i = 1; i < V.size(); i++){if (V[i].find(*it) == string::npos){reverse(V[i].begin(), V[i].end());if (V[i].find(*it) == string::npos){find = false;break;}}}if (find && (*it).size() > max)max = (*it).size();}cout << max << endl;}return 0;}
