#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1000000007;
const long long MAX = 100005;
const long double PI = 3.14159265359;
const long double G = 9.807;
const long long INF = 1e18;
const long double EPS = 1e-6;
long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
bool isprime(long long a) {
  if (a == 2) return 1;
  if (!(a & 1)) return 0;
  for (long long i = 3; i * i <= a; i += 2)
    if (a % i == 0) return 0;
  return 1;
}
long long mpow(long long base, long long exponent, long long modulus) {
  if (modulus == 1) return 0;
  long long result = 1;
  base = base % modulus;
  while (exponent) {
    if (exponent % 2 == 1) result = (result * base) % modulus;
    exponent = exponent >> 1;
    base = (base * base) % modulus;
  }
  return result;
}
long long minv(long long a, long long mod) {
  long long _gcd = gcd(a, mod);
  assert(_gcd == 1);
  return mpow(a, mod - 2, mod);
}
long long t;
string g[MAX];
long long col[MAX];
int main() {
  ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  cin >> t;
  while (t--) {
    long long n, m;
    cin >> n >> m;
    for (long long i = 0; i < n; i++) {
      cin >> g[i];
    }
    for (long long i = 0; i < m; i++) col[i] = 0;
    for (long long j = 0; j < m; j++) {
      for (long long i = 0; i < n; i++) {
        if (g[i][j] == '.') col[j]++;
      }
    }
    long long ans = 1e12;
    for (long long i = 0; i < n; i++) {
      vector<long long> pos;
      long long ro = 0;
      for (long long j = 0; j < m; j++) {
        if (g[i][j] == '.') {
          col[j]--;
          ro++;
          pos.push_back(j);
        }
      }
      long long co = n;
      for (long long j = 0; j < m; j++) co = min(co, col[j]);
      for (auto it : pos) col[it]++;
      ans = min(ans, ro + co);
    }
    cout << ans << '\n';
  }
  return 0;
}
