#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using ll = long long;
#define rep(i, s, t) for (ll i = s; i < (ll)(t); i++)
#define all(x) begin(x), end(x)

template <class T> bool chmin(T& x, T y) {
	return x > y ? (x = y, true) : false;
}
template <class T> bool chmax(T& x, T y) {
	return x < y ? (x = y, true) : false;
}

struct io_setup {
	io_setup() {
		ios::sync_with_stdio(false);
		cin.tie(nullptr);
		cout << fixed << setprecision(15);
	}
} io_setup;

using mint = atcoder::modint998244353;

void solve() {
	int n, m;
	cin >> n >> m;
	atcoder::mcf_graph<ll, ll> g(n * m + n * 2 + 2);
	int st = n * m + n * 2, ed = st + 1;
	vector<vector<int>> a(m, vector<int>(n));
	rep(i, 0, n) rep(j, 0, m) cin >> a[j][i];
	ll shf = 1e9;
	rep(i, 0, n / 2) {
		g.add_edge(st, n * m + i, 1, 0);
	}
	rep(i, n / 2, n) {
		g.add_edge(n * m + n + i, ed, 1, 0);
	}
	rep(i, 0, m) {
		rep(j, 0, n - 1) {
			g.add_edge(i * n + j, i * n + j + 1, n, 0);
		}
		rep(j, 0, n) {
			g.add_edge(n * m + j, i * n + j, 1, a[i][j]);
			g.add_edge(i * n + j, n * m + n + j, 1, shf - a[i][j]);
		}
	}
	auto [fl, cs] = g.flow(st, ed);
	cout << fl * shf - cs << '\n';
}

int main() {
	int t = 1;
	// cin >> t;
	while (t--) solve();
}