#include <fstream>

using namespace std;

int n, m, i, j;
long long a[20][20], s[20], S, smax, s1;
bool v[20];

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[0])
    {
        j = m;
        while(v[j])
        {
            v[j] = 0;
            j--;
        }
        v[j] = 1;
        s1 = 0;
        for(i = 1;i <= n; i++)
        {
            S = 0;
            for(j = 1;j <= m; j++)
                if(v[j]) S -= a[i][j];
                else S += a[i][j];
            if(S < 0) S = (-1) * S;
            s1 += S;
        }
        if(s1 > smax) smax = s1;
    }
    fout << smax;
    return 0;
}