#include <bits/stdc++.h>
using namespace std;


int n,m,a[17][17],linie[17]={0},coloana[17]={0},total=0 ;

void Flip(int linie)
{
    for(int j=1;j<=m;++j)
        a[linie][j]*=-1;
}

void check()
{
    int sum = 0;
    for(int j=1;j<=m;++j)
    {
        int sumc = 0;
        for(int i=1;i<=n;++i)sumc+=a[i][j];
            if(sumc < 0)sumc=-sumc;
        sum += sumc;
    }
    total = max(total,sum);
}

void bkt(int k)
{
    if(k > n)check();
    else
    {
        Flip(k);
        bkt(k+1);
        Flip(k);
        bkt(k+1);
    }
}

int main()
{
    freopen("flip.in","r",stdin);

    cin >> n >> m;
    for(int i=1;i<=n;++i)
        for(int j=1;j<=m;++j)
    {
        cin >> a[i][j];
    }

    bkt(1);

    freopen("flip.out","w",stdout);
    cout << total;

}