#include <bits/stdc++.h>

using namespace std;

ifstream fin("flip.in");
ofstream fout("flip.out");



long long int n, m, a[17][17], line[17], colum[17], sum, maxim;

void BT(int k)
{
    if(k == n+1)
    {
      long long int sum2;
        sum2 = sum;
        for(int i = 1; i <= m; i++)
           if(colum[i] < 0)
            {
                sum2 -= colum[i];
                sum2 += -colum[i];

            }
        maxim = max(maxim, sum2);



    }

    else
        for(int i = 0; i <= 2; i = i+2)
        {




                sum += (i-1)*line[k];
                for(int j = 1; j <= m; j++)
                    colum[j] += (i-1) * a[k][j];

                BT(k+1);
                sum -= (i-1)*line[k];

                for(int j = 1; j <= m; j++)
                    colum[j] -= (i-1) * a[k][j];


        }



}

int main()
{
    fin >> n >> m;
    for(int i = 1; i <= n; i++)
        for(int j = 1; j <= m; j++)
          {
               fin >> a[i][j];
                line[i] += a[i][j];
          }

    BT(1);

    fout << maxim;

    return 0;
}