#include <bits/stdc++.h>

using i64 = long long;
template<class T>
constexpr T power(T a, i64 b) {
    T res = 1;
    for (; b; b /= 2, a *= a) {
        if (b % 2) {
            res *= a;
        }
    }
    return res;
}

constexpr i64 mul(i64 a, i64 b, i64 p) {
    i64 res = a * b - i64(1.L * a * b / p) * p;
    res %= p;
    if (res < 0) {
        res += p;
    }
    return res;
}
template<i64 P>
struct MLong {
    i64 x;
    constexpr MLong() : x{} {}
    constexpr MLong(i64 x) : x{norm(x % getMod())} {}
    
    static i64 Mod;
    constexpr static i64 getMod() {
        if (P > 0) {
            return P;
        } else {
            return Mod;
        }
    }
    constexpr static void setMod(i64 Mod_) {
        Mod = Mod_;
    }
    constexpr i64 norm(i64 x) const {
        if (x < 0) {
            x += getMod();
        }
        if (x >= getMod()) {
            x -= getMod();
        }
        return x;
    }
    constexpr i64 val() const {
        return x;
    }
    explicit constexpr operator i64() const {
        return x;
    }
    constexpr MLong operator-() const {
        MLong res;
        res.x = norm(getMod() - x);
        return res;
    }
    constexpr MLong inv() const {
        assert(x != 0);
        return power(*this, getMod() - 2);
    }
    constexpr MLong &operator*=(MLong rhs) & {
        x = mul(x, rhs.x, getMod());
        return *this;
    }
    constexpr MLong &operator+=(MLong rhs) & {
        x = norm(x + rhs.x);
        return *this;
    }
    constexpr MLong &operator-=(MLong rhs) & {
        x = norm(x - rhs.x);
        return *this;
    }
    constexpr MLong &operator/=(MLong rhs) & {
        return *this *= rhs.inv();
    }
    friend constexpr MLong operator*(MLong lhs, MLong rhs) {
        MLong res = lhs;
        res *= rhs;
        return res;
    }
    friend constexpr MLong operator+(MLong lhs, MLong rhs) {
        MLong res = lhs;
        res += rhs;
        return res;
    }
    friend constexpr MLong operator-(MLong lhs, MLong rhs) {
        MLong res = lhs;
        res -= rhs;
        return res;
    }
    friend constexpr MLong operator/(MLong lhs, MLong rhs) {
        MLong res = lhs;
        res /= rhs;
        return res;
    }
    friend constexpr std::istream &operator>>(std::istream &is, MLong &a) {
        i64 v;
        is >> v;
        a = MLong(v);
        return is;
    }
    friend constexpr std::ostream &operator<<(std::ostream &os, const MLong &a) {
        return os << a.val();
    }
    friend constexpr bool operator==(MLong lhs, MLong rhs) {
        return lhs.val() == rhs.val();
    }
    friend constexpr bool operator!=(MLong lhs, MLong rhs) {
        return lhs.val() != rhs.val();
    }
};

template<>
i64 MLong<0LL>::Mod = 1;

template<int P>
struct MInt {
    int x;
    constexpr MInt() : x{} {}
    constexpr MInt(i64 x) : x{norm(x % getMod())} {}
    
    static int Mod;
    constexpr static int getMod() {
        if (P > 0) {
            return P;
        } else {
            return Mod;
        }
    }
    constexpr static void setMod(int Mod_) {
        Mod = Mod_;
    }
    constexpr int norm(int x) const {
        if (x < 0) {
            x += getMod();
        }
        if (x >= getMod()) {
            x -= getMod();
        }
        return x;
    }
    constexpr int val() const {
        return x;
    }
    explicit constexpr operator int() const {
        return x;
    }
    constexpr MInt operator-() const {
        MInt res;
        res.x = norm(getMod() - x);
        return res;
    }
    constexpr MInt inv() const {
        assert(x != 0);
        return power(*this, getMod() - 2);
    }
    constexpr MInt &operator*=(MInt rhs) & {
        x = 1LL * x * rhs.x % getMod();
        return *this;
    }
    constexpr MInt &operator+=(MInt rhs) & {
        x = norm(x + rhs.x);
        return *this;
    }
    constexpr MInt &operator-=(MInt rhs) & {
        x = norm(x - rhs.x);
        return *this;
    }
    constexpr MInt &operator/=(MInt rhs) & {
        return *this *= rhs.inv();
    }
    friend constexpr MInt operator*(MInt lhs, MInt rhs) {
        MInt res = lhs;
        res *= rhs;
        return res;
    }
    friend constexpr MInt operator+(MInt lhs, MInt rhs) {
        MInt res = lhs;
        res += rhs;
        return res;
    }
    friend constexpr MInt operator-(MInt lhs, MInt rhs) {
        MInt res = lhs;
        res -= rhs;
        return res;
    }
    friend constexpr MInt operator/(MInt lhs, MInt rhs) {
        MInt res = lhs;
        res /= rhs;
        return res;
    }
    friend constexpr std::istream &operator>>(std::istream &is, MInt &a) {
        i64 v;
        is >> v;
        a = MInt(v);
        return is;
    }
    friend constexpr std::ostream &operator<<(std::ostream &os, const MInt &a) {
        return os << a.val();
    }
    friend constexpr bool operator==(MInt lhs, MInt rhs) {
        return lhs.val() == rhs.val();
    }
    friend constexpr bool operator!=(MInt lhs, MInt rhs) {
        return lhs.val() != rhs.val();
    }
};

template<>
int MInt<0>::Mod = 1;

template<int V, int P>
constexpr MInt<P> CInv = MInt<P>(V).inv();

constexpr i64 P = 1E18 + 9;
using Z = MLong<P>;

constexpr i64 B1 = 114514;
constexpr i64 B2 = 1145141;

std::pair<int, int> solve(std::vector<std::string> a, int n, int m) {
    std::vector<Z> s(n);
    for (int i = 0; i < n; i++) {
        for (auto c : a[i]) {
            s[i] = s[i] * B1 + c;
        }
    }
    
    std::vector<Z> h1(n + 1), h2(n + 1), pw(n + 1);
    pw[0] = 1;
    
    auto get = [&](auto &h, int l, int r) {
        return h[r] - h[l] * pw[r - l];
    };
    for (int i = 0; i < n; i++) {
        h1[i + 1] = h1[i] * B2 + s[i];
        h2[i + 1] = h2[i] * B2 + s[n - 1 - i];
        pw[i + 1] = pw[i] * B2;
    }
    
    int l = 0, r = n;
    
    for (int i = l; 2 * i <= l + r; i++) {
        if (get(h1, l, i) == get(h2, n - (2 * i - l), n - i)) {
            l = i;
        }
    }
    for (int i = r; 2 * i >= l + r; i--) {
        if (get(h1, i, r) == get(h2, n - i, n - (2 * i - r))) {
            r = i;
        }
    }
    
    return {l, r};
}

constexpr int dx[] = {0, 0, -1, 1};
constexpr int dy[] = {-1, 1, 0, 0};

void solve() {
    int n, m;
    std::cin >> n >> m;
    
    std::vector<std::string> a(n), b(m);
    for (int i = 0; i < n; i++) {
        std::cin >> a[i];
        for (int j = 0; j < m; j++) {
            b[j] += a[i][j];
        }
    }
    
    auto [xl, xr] = solve(a, n, m);
    auto [yl, yr] = solve(b, m, n);
    
    std::vector vis(n, std::vector<bool>(m));
    int ans = 0;
    for (int i = xl; i < xr; i++) {
        for (int j = yl; j < yr; j++) {
            if (!vis[i][j] && a[i][j] == '0') {
                ans++;
                std::queue<std::pair<int, int>> q;
                q.emplace(i, j);
                vis[i][j] = true;
                
                while (!q.empty()) {
                    auto [x, y] = q.front();
                    q.pop();
                    
                    for (int k = 0; k < 4; k++) {
                        int nx = x + dx[k];
                        int ny = y + dy[k];
                        
                        if (xl <= nx && nx < xr && yl <= ny && ny < yr && !vis[nx][ny] && a[nx][ny] == '0') {
                            q.emplace(nx, ny);
                            vis[nx][ny] = true;
                        }
                    }
                }
            }
        }
    }
    std::cout << ans << "\n";
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    
    std::cout << std::fixed << std::setprecision(10);
    
    int t;
    std::cin >> t;
    
    while (t--) {
        solve();
    }
    
    return 0;
}