{

int t;

cin >> t;

while (t--)

{

int n, m;

cin >> n >> m;

int a[n + 1][m + 1];

for (int i = 1; i <= n; i++)

{

for (int j = 1; j <= m; j++)

cin >> a[i][j];

}

int dp[n + 1][m + 1] = {};

int result = 0;

for (int i = 1; i <= n; i++)

{

for (int j = 1; j <= m; j++)

{

if (a[i][j] != 0)

{

dp[i][j] = min({dp[i - 1][j - 1], dp[i - 1][j], dp[i][j - 1]}) + 1;

result = max(result, dp[i][j]);

}

}

}

cout << dp[n][m] << endl;

}

system("pause");

return 0;

}