#include <cstdio>
#include <algorithm>
using namespace std;

const int NMAX = 20;

int N, M, A[NMAX][NMAX], Ans;

int main()
{
    freopen("flip.in", "r", stdin);
    freopen("flip.out", "w", stdout);

    scanf("%i %i", &N, &M);
    for(int i = 0; i < N; ++ i)
        for(int j = 0; j < M; ++ j)
            scanf("%i", &A[i][j]);

    for(int Conf = 0; Conf < (1 << N); ++ Conf)
    {
        for(int i = 0; i < N; ++ i)
            if(Conf & (1 << i))
                for(int j = 0; j < M; ++ j)
                    A[i][j] *= -1;

        int Total = 0;
        for(int j = 0; j < M; ++ j)
        {
            int S1 = 0, S2 = 0;
            for(int i = 0; i < N; ++ i)
                S1 += A[i][j], S2 += -A[i][j];
            Total += max(S1, S2);
        }
        Ans = max(Ans, Total);

        for(int i = 0; i < N; ++ i)
            if(Conf & (1 << i))
                for(int j = 0; j < M; ++ j)
                    A[i][j] *= -1;
    }

    printf("%i\n", Ans);
}