#include <iostream>
#include <fstream>
#include <queue>
#define ll long long
#define inf 1000000005
using namespace std;
ll n,m,r,c;
priority_queue <ll> q;
ll M[17][17];
ll st[17];
ll v[17];
ll Max=-inf;
void Check()
{
    ll i,j;
    ll s=0,s1,s2;

    for (j=1;j<=m;j++)
    {
        s1 = s2 = 0;
        for (i=1;i<=n;i++)
            if (st[i]==0)
                s1 +=M[i][j],
                s2 -=M[i][j];
            else
                s1 -=M[i][j],
                s2 +=M[i][j];
        s += max(s1 , s2);
    }

    Max = max(Max , s);
}

void Back(ll i)
{
    if (i>n)
    {
        Check();
    }
    else
    {
         st[i]=1;
         Back(i+1);
         st[i]=0;
         Back(i+1);
    }
}
int main()
{
    ifstream in("flip.in");
    ofstream out("flip.out");
    in>>n>>m;
    ll i,j;
    for (i=1;i<=n;i++)
        for (j=1;j<=m;j++)
            in>>M[i][j];
    Back(1);
out<<Max<<"\n";
out.close();
in.close();
return 0;
}