1 #include<iostream>
 2 #include<string>
 3 #include<vector>
 4 #include<cmath>
 5 using namespace std;
 6 
 7 bool compute(string s1, string s2){
 8     if(s1.length() != s2.length())
 9         return false;
10     bool flag = false;
11     for(int i=0;i<s1.length();i++){
12         flag =(abs(s1[i]-s2[i]) == 19 || abs(s1[i]-s2[i]) == 4);
13         if(!flag)
14             break;
15     }
16     return flag;
17 }
18 vector<string> strands;
19 
20 int main(){
21     int caseNums;
22     cin >> caseNums;
23     while(caseNums--){
24         int rows;
25         string temp;
26         int result =0;
27 
28         cin >> rows;
29         strands.resize(rows);
30         strands.clear();
31         for(int i=1;i<=rows;i++){
32             cin >> temp;
33             strands.push_back(temp);
34         }
35 
36         for(int i=0;i<strands.size();i++){
37             if(strands[i] =="00")
38                 continue;
39             for(int j=i+1;j<strands.size();j++){
40                 if(strands[j]=="0")
41                     continue;
42                 if(compute(strands[i],strands[j]))
43                 {
44                     strands[i] ="00";
45                     strands[j] ="00";
46                     result++;
47                     break;
48                 }
49             }
50         }
51         cout<<result<<endl;
52     }
53     return 0;
54 }