#include <bits/stdc++.h>
using namespace std;

#define FAST ios_base::sync_with_stdio(false);cin.tie(NULL);
using ll = long long;

int main() {
  FAST;
  
  int tc = 1, ti;
  cin >> tc;

  for (ti = 1; ti <= tc; ++ti) {
    ll n, m, i, j, k, ans, curr;
    cin >> n >> m;

    vector<string> a(n);
    for (i = 0; i < n; ++i) cin >> a[i];

    vector<vector<ll>> pf(n, vector<ll>(m));
    vector<vector<ll>> sf(n, vector<ll>(m));
    for (j = 0; j < m; ++j) {
      pf[0][j] = 1;
      for (i = 1; i < n; ++i) {
        if (a[i][j] == a[i-1][j]) pf[i][j] = pf[i-1][j] + 1;
          else pf[i][j] = 1;
      }
      for (i = 1; i < n; ++i) pf[i][j] = max(pf[i][j], pf[i-1][j]);

      sf[n-1][j] = 1;
      for (i = n-2; i >= 0; --i) {
        if (a[i][j] == a[i+1][j]) sf[i][j] = sf[i+1][j] + 1;
          else sf[i][j] = 1;
      }
      for (i = n-2; i >= 0; --i) sf[i][j] = max(sf[i][j], sf[i+1][j]);
    }

    ans = 0;
    for (j = 0; j < m; ++j) ans += pf[n-1][j];

    for (i = 0; i < n-1; ++i) {
      curr = 0;
      for (j = 0; j < m; ++j) curr += max(pf[n-1][j], pf[i][j] + sf[i+1][j]);
      ans = max(ans, curr);
    }

    vector<vector<ll>> L(m, vector<ll>(26, 0));
    vector<vector<ll>> R(m, vector<ll>(26, 0));
    for (i = 0; i < n; ++i) {
      for (j = 0; j < m; ++j) {
        for (k = 0; k < 26; ++k) {
          if (a[i][j] == (char)'a'+k) R[j][k] += 1;
        }
      }
    }

    ans = 0;
    for (j = 0; j < m; ++j) {
      ans += *max_element(R[j].begin(), R[j].end());
    }

    for (i = 0; i < n; ++i) {
      for (j = 0; j < m; ++j) {
        for (k = 0; k < 26; ++k) {
          if (a[i][j] == (char)'a'+k) {
            L[j][k] += 1;
            R[j][k] -= 1;
          }
        }
      }
      curr = 0;
      for (j = 0; j < m; ++j) {
        curr += *max_element(L[j].begin(), L[j].end());
        curr += *max_element(R[j].begin(), R[j].end());
      }
      ans = max(ans, curr);
    }

    cout << ans << "\n";
  }

  return 0;
}