#include <stdio.h>
#include <stdlib.h>

int main(int argc, char *argv[])
{
    int n, m, **mat;
    unsigned int i, j, k, l;
    int max = 0;
    freopen("flip.in", "r", stdin);
    freopen("flip.out", "w", stdout);

    scanf("%d %d", &n, &m);
    mat = malloc((n + 1) * sizeof(*mat));
    for (i = 0; i < n; i ++) {
        mat[i] = malloc((m + 1) * sizeof(*mat[i]));
    }

    for (i = 0; i < n; i ++) {
        for (j = 0; j < m; j ++) {
            scanf("%d", &mat[i][j]);
        }
    }

    for (i = 0; i < (1 << n); i ++)
    {
        int sum = 0;

        for (k = 0; k < m; k ++) {
            int col_sum = 0;
            for (j = 0; j < n; j ++) {
                if (i & (1 << j)) {
                    col_sum -= mat[j][k];
                } else {
                    col_sum += mat[j][k];
                }
            }

            if (col_sum < 0) {
                sum -= col_sum;
            } else {
                sum += col_sum;
            }
        }

        if (sum > max)
            max = sum;
    }

    printf("%d\n", max);
    return 0;
}