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#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    const ll MOD = 1e9l + 7;
    const ll inv2 = 5e8l + 4;

    ll n, k;
    cin >> n >> k;

    ll tmp;
    for (ll i = 0; i < n; i++)
        for (ll j = 0; j < k; j++)
            cin >> tmp;

    ll p = n * (n - 1);
    ll q = 4;


    ll gcd = __gcd(p, q);
    p /= gcd;
    q /= gcd;

    if (q == 1)
        cout << p << "\n";
    else
        cout << (p * inv2) % MOD << "\n";

    return 0;
}