#include<stdio.h>
#define BIT(k)(1<<(k))
#define max(a, b) (a>b?a:b)
using namespace std;

int n, m, tabla[20][20];
int scol[20], s, smax = -1000000000;

int main(void){
    freopen("flip.in" , "r", stdin );
    freopen("flip.out", "w", stdout);
    scanf("%d%d", &n, &m);
    for(int i = 0; i < n; i++){
        for(int j= 0; j < m; j++){
            scanf("%d", &tabla[i][j]);
        }
    }
    for(int p = 0; p < BIT(n); p++){
        s = 0;
        for(int j = 0; j < m; j++){
            scol[j] = 0;
            for(int i = 0; i < n; i++){
                if((p & BIT(i)) != 0){
                    s -= tabla[i][j];
                    scol[j] -= tabla[i][j];
                }else{
                     s += tabla[i][j];
                    scol[j] += tabla[i][j];
                }
            }
        }
        for(int j = 0; j < m; j++){
            if(scol[j] < 0){
                s -= 2* scol[j];
            }
            smax = max(smax, s);
        }
    }
    printf("%d", smax);
    return 0;
}