#include <stdio.h>

int main()
{
    FILE *f=fopen("flip.in","r"),*g=fopen("flip.out","w");
    int i=0,j=0,k=0,m=0,n=0, colSum=0;
    long long max = -300000000, mSum=0;
    fscanf(f,"%d %d", &n, &m);
    n = n % 17;
    m = m % 17;
    /*printf("sssss %d %d\n", n, m);*/
    long long a[n][m];
    for(i=0;i<n;i++)
    {
        for(j=0; j<m; j++)
        {
            fscanf(f, "%d", &a[i][j]);
            /*printf("--->i=%d\tj=%d\t%d\n", i, j, a[i][j]);*/
        }
    }
     for (k = -1; k < n; k++)
     {
        mSum = 0;
        for (j = 0; j < m; j++)
        {
            colSum = 0;
            for (i = 0; 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, "%lld", max);
    fclose(f);
    fclose(g);

    return 0;
}