#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic warning "-Wunused-function"
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, m;
  cin >> n >> m;
  int s = n + m, t = s + 1;
  mcf_graph<int, ll> g(t + 1);
  constexpr int M = 1e9;
  rep(i, n) {
    VI a(m);
    rep(j, m) cin >> a[j];
    if (i < n / 2) {
      g.add_edge(s, i, 1, 0);
      rep(j, m) g.add_edge(i, n + j, 1, a[j]);
    } else if (i >= (n + 1) / 2) {
      g.add_edge(i, t, 1, 0);
      rep(j, m) g.add_edge(n + j, i, 1, M - a[j]);
    }
  }
  auto [f, c] = g.flow(s, t);
  assert(f == n / 2);
  c -= (ll)M * f;
  cout << -c << '\n';
}