#include <fstream>
#include <vector>
#include <iostream>
using namespace std;
ifstream f("flip.in");
ofstream g("flip.out");
int n, m, v[21][21];
vector<int> lin_flip;
long long a = 0;
void flip(int k)
{int i;
    for(i = 1; i<=m; i++)
    {
        v[k][i] = v[k][i] * (-1);
    }
}
void backtracking(int k)
{int i, j;
long long sumcol,total;
    if(k == n)
    {
        for( i = 0; i<lin_flip.size(); i++)
        {
            flip(lin_flip[i]);
        }
sumcol = 0;
        total = 0;
        for( j = 1; j<=m; j++)
        {
            sumcol = 0;
            for( i = 1; i<=n; i++)
            {
                sumcol =sumcol+ v[i][j];
            }
            total=total+ abs(sumcol);
        }
        a = max(a, total);
for( i = 0; i<lin_flip.size(); i++)
        {
            flip(lin_flip[i]);
        }
        return;
    }
lin_flip.push_back(k);
    backtracking(k+1);
    lin_flip.pop_back();
    backtracking(k+1);
}
int main()
{int i,j;
    f>>n>>m;
    for( i = 1; i<=n; i++)
    {
        for( j = 1; j<=m; j++)
        {
            f>>v[i][j];
        }
    }
    backtracking(1);
g<<a;
    return 0;
}