rt

const int N = 1e6 + 7;
int n, m, l, r, mid, flg, ans;
string s[N], ss[N];

inline bool check(int x) {
    int bg = x <= mid ? l : x + 1, ed = x <= mid ? x : r;
    for (int i = 1; i <= n; ++i) for (int j = bg; j <= ed; ++j)
        if (s[i][j] ^ s[i][x + x - j + 1]) return false;
    return true;
}
inline void dfs(int x, int y) {
    if (x < 1 || x > n || y < l || y > r || s[x][y] == '1') return ;
    s[x][y] = '1';
    dfs(x + 1, y);
    dfs(x - 1, y);
    dfs(x, y + 1);
    dfs(x, y - 1);
}

signed main() {
    // freopen("", "r", stdin);
    // freopen("", "w", stdout);
    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    for (int T = read<int>(); T--; ) {
        read(n, m), ans = 0;
        for (int i = 1; i <= n; ++i) read(s[i]), s[i] = ' ' + s[i];
        l = 1, r = m, flg = 1;
        solve: {
            mid = l + r - 1 >> 1;
            for (int i = l + r >> 1; l <= i && i < r; i = l + r - i - (i > mid))
                if (check(i)) {
                    if (i <= mid) l = i + 1;
                    else r = i;
                    goto solve;
                }
        }
        if (flg) { // 旋转
            int k = r - l + 1;
            for (int i = 1; i <= n; ++i) ss[i] = s[i].substr(l, k);
            for (int i = 1, j; i <= k; ++i) for (s[i] = " ", j = 1; j <= n; ++j)
                s[i] += ss[j][i - 1];
            l = 1, r = n, n = k, flg = 0;
            goto solve;
        }
        for (int i = 1; i <= n; ++i) for (int j = l; j <= r; ++j)
            if (s[i][j] == '0') dfs(i, j), ++ans;
        print(ans, '\n');
    }
    return Flush;
}

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