#include <bits/stdc++.h>

using namespace std;
ifstream in("flip.in");
ofstream out("flip.out");
const int MAX = 16;
int Matrix[MAX+1][MAX+1];
int Maxim;
int N,M;
int F[MAX+1];

inline void Update()
{
    int NR = 0;
    for ( int j = 1 ; j <= M ; ++j)
    {
        int C = 0;
        for ( int i = 1; i <= N ; ++i)
            C += Matrix[i][j] * F[i];
        NR = NR + abs(C);

        Maxim = max(Maxim,NR);
    }
}

void Back(int K)
{
    if(K <= N)
    {
        F[K] = 1;
        Back(K+1);
        F[K] = -1;
        Back(K+1);
    }
    else Update();
}

int main()
{
   in >> N >> M;
   for ( int i = 1 ; i <= N ; ++i)
    for ( int j = 1; j <= M ; ++j)
      in >> Matrix[i][j];

   Back(1);

   out << Maxim;
}