#include <bits/stdc++.h>
#define ll long long

using namespace std;

ifstream fin("flip.in");
ofstream fout("flip.out");

ll n,m,v[20][20];
ll sumacol[20],maxim;

void bkt(int i)
{
    if(i==n+1)
    {
        ll sum=0;
        for(int j=1; j<=m; j++)
        {
            sum+=max(sumacol[j],-sumacol[j]);
        }
        maxim=max(maxim,sum);
        return;
    }
    bkt(i+1);
    for(int j=1; j<=m; j++)
    {
        sumacol[j]-=v[i][j];
        v[i][j]=-v[i][j];
        sumacol[j]+=v[i][j];
    }
    bkt(i+1);
}

int main()
{
    fin>>n>>m;
    for(int i=1; i<=n; i++)
        for(int j=1; j<=m; j++)
        {
            fin>>v[i][j];
            sumacol[j]+=v[i][j];
        }
    bkt(1);
    fout<<maxim;
    return 0;
}