// compile: g++ -o data data.cpp -std=gnu++20
// run: ./data < data.in
#include <bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#define int long long
#define MAXN 300010

using namespace std;

int n, m;

int comp(vector<int> a) {
    if (a.size() <= 1) return 0;
    sort(a.begin(), a.end());
    vector<int> diff, sum, suffix(a.size(), 0);
    diff.clear();
    sum.clear();
    for (int i = 1; i < a.size(); ++i) {
        diff.push_back(a[i] - a[i - 1]);
        if (i == 1) sum.push_back(diff[i - 1]);
        else sum.push_back(sum[i - 2] + diff[i - 1]);
    }
    for (int i = 0; i < sum.size(); ++i) {
        int ind = sum.size() - i - 1;
        if (!i) suffix[ind] = sum[ind];
        else suffix[ind] = suffix[ind + 1] + sum[ind];
    }
    int len = diff.size();
    int ans = suffix[0];
    for (int i = 1; i < len; ++i) {
        ans += suffix[i] - (sum[i - 1] * (len - i));
        // cout << suffix[i] - (diff[i - 1] * (len - i)) << endl;
        // cout << suffix[i] << " " << sum[i - 1] << " " << (len - i) << endl;
    }
    // for (int i = 0; i < len; ++i) cout << suffix[i] << endl;
    return ans;
}

int32_t main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int _; cin >> _;
    while (_--) {
        cin >> n >> m;
        vector<int> a[MAXN];
        for (int i = 0; i < n; ++i) {
            for (int j = 0; j < m; ++j) {
                int x; cin >> x;
                a[j].push_back(x);
            }
        }
        int total = 0;
        for (int i = 0; i < m; ++i) {
            total += comp(a[i]);
        }
        cout << total << endl;
    }

    return 0;
}