#include <bits/stdc++.h>
#define pb push_back
#define pf push_front
#define pi 2*acos(0.0)
#define f first
#define s second
#define inf INT_MAX
#define MXN 500001
#define endl "\n"
#define eps 1e-6
#define mod 1000000007
#define all(x) x.begin(), x.end()
#define rev(x) x.rbegin(), x.rend()
#define spc(x) cout << fixed << setprecision(x)
#define fastio {ios_base::sync_with_stdio(false); cin.tie(NULL);}
#define test ll t; cin >> t; while (t--)

typedef long long ll;
using namespace std;

void solve()
{
   ll n,m;
   cin>>n>>m;
   vector<string> v;
   for(int i=0;i<n;i++){
        string s; cin>>s;
         v.pb(s);
   }
   ll ans=0; 
   map<ll,vector<char>> mp,mpp;   
   for(int i=0;i<n;i++){
        string ss = v[i];

        for(int j=0;j<m;j++){
              mp[j].pb(ss[j]);
              if(i<n-1){
                   mpp[j].pb(ss[j]);
             }              
        }

   }

   for(int i=0;i<m;i++){
         map<char,ll> mp1,mpp1;
         for(int j=0;j<mp[i].size();j++){
              mp1[mp[i][j]]++;
         }
         for(int j=0;j<mpp[i].size();j++){
              mpp1[mpp[i][j]]++;
         }
         ll mx = 0;
         ll mx1 = 0;  
         for(auto x:mp1){
               // cout<<x.f<<" "<<x.s<<endl;
               mx = max(mx,x.s);
         }
         for(auto x:mpp1){
               // cout<<x.f<<" "<<x.s<<endl;
               mx1 = max(mx1,x.s);
         }
         ans+=mx;

         if(mx1==mx){
              ans++;
         }
   }
   cout<<ans<<endl;
}
int32_t main()
{
   fastio
   int t = 1;
   cin >> t;
   while (t--) {
      solve();
   }
   return 0;
}