#include <iostream>

using namespace std;

#define N 16

int ma[N+1][N+1];

int main()
{
    //ifstream cin ("flip.in");
    //ofstream cout ("flip.out");

    int n,m,l,c,i,c1,s,x;

    cin >> n >> m;
    for (l=0; l<n; l++)
        for (c=0; c<m; c++)
            cin >> ma[l][c];

    x = 0;
    for (i=0; i<(1 << n); i++){
        for (l=0; l<n; l++)
            if (i & (1 << l))
                for (c=0; c<m; c++)
                    ma[l][c] =- ma[l][c];

        s = 0;
        for (c=0; c<m; c++){
            c1=0;
            for (l=0; l<n; l++)
                c1 += ma[l][c];

            s += abs(c1);
        }

        for (l=0; l<n; l++)
            if (i & (1 << l))
                for (c=0; c<m; c++)
                    ma[l][c] =- ma[l][c];

        x = max(x, s);
    }

    cout << x << '\n';

    return 0;
}