#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 max1 = -3000000000, mSum=0;
    fscanf(f,"%d %d", &n, &m);
    n = n % 17;
    m = m % 17;

    int a[n][m];
    for(i=0; i<n; i++)
    {
        for(j=0; j<m; j++)
        {
            fscanf(f, "%d", &a[i][j]);
            printf("%d\t", a[i][j]);
        }
        printf("\n");
    }
     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];
                    printf("1==>j=%d i=%d cell=%d colSum=%d\n", j, i, a[i][j], colSum);
                }
                else {
                    colSum = colSum + a[i][j];
                    printf("2==>j=%d i=%d cell=%d colSum=%d\n", j, i, a[i][j], colSum);
                }
            }

             printf("==>j=%d colSum=%d\n", j, colSum);

            if (colSum > 0)
                mSum = mSum + colSum;
            else
                mSum = mSum - colSum;
        }
        printf("-->k=%d mSum=%lld\n", k, mSum);

        if (mSum > max1)
        {
            max1 = mSum;
        }
     }
    fprintf(g, "%lld", max1);
    fcloseall();

    return 0;
}