#include <stdio.h>

int main()
{
    FILE *f=fopen("flip.in","r"),*g=fopen("flip.out","w");
    int i,j,k,m,n, colSum;
    long max = -300000000, mSum;
    fscanf(f,"%d %d",&n, &m);
    n = n % 17;
    m = m % 17;
    int a[n][m];

    for(i=1;i<=n;i++)
    {
        for(j=1;j<=m;j++)
        {
            fscanf(f,"%d",&a[i][j]);
        }
    }

     for (k = 0; k <= n; k++)
     {
        mSum = 0;
        for (j = 1; j <= m; j++)
        {
            colSum = 0;
            for (i = 1; i <= n; i++)
            {
                if (i == k)
                {
                    colSum = colSum - a[i][j];
                } else
                {
                    colSum = colSum + a[i][j];
                }
            }

            if (colSum > 0)
            {
                mSum =mSum + colSum;
            } else
            {
                mSum =mSum - colSum;
            }
        }

        if (mSum > max)
        {
            max = mSum;
        }
     }
    fprintf(g, "%ld", max);
    fclose(f);
    fclose(g);

    return 0;
}