#include <stdio.h>#include <string.h>#include <string>#include <algorithm>#include <iostream>using namespace std;int cmp(const string p,const string q){ return p.length()<q.length();}int main(){ freopen("read.txt", "r", stdin); string str[200]; int T; scanf("%d", &T); while(T--) { int n; scanf("%d", &n); string tp; for(int i=0; i<n; i++) cin >> str[i]; sort(str, str+n, cmp); int length = str[0].length(); int result = 0; for(int i=0; i<length; i++) { bool sign = 1; tp.clear(); for(int j=i+1; j<=length && sign; j++) { tp.assign(str[0], i, j-i); for(int k =0; k<n; k++) { if(str[k].find(tp) == str[k].npos) { reverse(str[k].begin(), str[k].end() ); if(str[k].find(tp) == str[k].npos) {sign = 0; break;} } } if(sign) { if(result < j-i) result = j-i; } } } printf("%d\n", result); } return 0;}