#include<bits/stdc++.h>

#pragma GCC optimize("O3")
#pragma GCC target("avx2")
#pragma GCC optimize("unroll-loops")

#define all(s) s.begin(),s.end()
#define rc(x) return cout<<x<<endl,0
#define forn(i,n) for(int i=0;i<int(n);i++)
#define len(a) (int) (a).size()

#define pb push_back
#define mp make_pair
#define fr first
#define sc second

typedef long long ll;
typedef long double ld;

const int nmax=2e5+3;
const int mod=998244353;
const ll inf=0x3f3f3f3f3f3f3f3f;

/*===================*\
      comentarii:
\*===================*/

using namespace std;

int n,m,a[25][25],s,aux;

void control()
{
    aux=0;
    for(int i=1;i<=n;i++)
    {
        int auxx=0;
        for(int j=1;j<=m;j++)
            auxx+=a[i][j];
        if(auxx<0) auxx=-auxx;
        aux+=auxx;
    }
    s=max(s,aux);
}

void back(int k)
{
    if(k>m) control(); else
    {
        back(k+1);
        for(int i=1;i<=n;i++) a[i][k]=-a[i][k];
        back(k+1);
    }
}

int main()
{
    freopen("flip.in","r",stdin);
    freopen("flip.out","w",stdout);
    cin>>n>>m;
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++) cin>>a[i][j];
    back(1);
    cout<<s;
}