#include <fstream>
 #define DIM 17
 using namespace std;
 int a[DIM][DIM], v[DIM];
 int n, m, i, j, s, sum ,maxim;
 int main(){
     
 ifstream fin("flip.in");
 ofstream fout("flip.out");
 
 fin >> n >> m;
 
 for (i = 1; i <= n; i++)
 for (j = 1; j <= m; j++)
    fin >> a[i][j];
    
 while (v[1] == 0) {
    j = m;
    while (v[j] == 1) {
        v[j] = 0;
        j -- ;
 }
    v[j] = 1;
    sum = 0;
    for (i = 1; i <= n; i++) {
        s = 0;
    for (j = 1; j <= m; j++)
    if (v[j] == 0)
        s += a[i][j];
    else
        s -= a[i][j];
    if (s > 0)
        sum += s;
    else
        sum -= s;
 }
    if (sum > maxim)
        maxim = sum;
 }
 
 fout << maxim;
 
 return 0;
 }