#include <stdio.h>
int n, m, i, j;
long int s1[16], s2[16], s, v[16][16];
int main()
{
    freopen("flip.in", "r", stdin);
    freopen("flip.out", "w", stdout);
    scanf("%d %d", &n, &m);
    for (i=1; i<=n; i++)
    {
        for (j=1; j<=m; j++)
        {
            scanf("%d ", &v[i][j]);
            s1[i]=s1[i]+v[i][j];
            s2[i]=s2[i]+((-1)*v[i][j]);
        }
        if (s2[i]>s1[i])
        {
           for (j=1; j<=m; j++) v[i][j]=(-1)*v[i][j];
        }
        scanf("\n");
    }

    for (i=1; i<=m; i++)
    {
        s1[i]=0;
        s2[i]=0;
        for (j=1; j<=n; j++)
        {
            s1[i]=s1[i]+v[i][j];
            s2[i]=s2[i]+((-1)*v[i][j]);
        }
        if (s1[i]>s2[i]) s=s+s1[i];
        else s=s+s2[i];
    }
    printf("%d", s);
    return 0;
    }