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

ifstream fin("flip.in");
ofstream fout("flip.out");
int v[17][17],n,m,i,j,k,sum,ans,matSum;

void citire()
{
    fin>>n>>m;
    for(i=1 ; i<=n ; ++i)
        for(j=1 ; j<=m ; ++j)
            fin>>v[i][j];
}


int main()
{
    citire();
    for(k=0 ; k<=n ; ++k)
    {
        matSum=0;
        for(i=1 ; i<=n ; ++i )
        {
            sum=0;
            for(j=m ; j>=1 ; --j)
            {
                if( k & ( 1 << ( j - 1 ) ) )
                    sum += v[i][j]*-1;
                else
                    sum += v[i][j];
            }
            if( sum < 0 )
                sum*=-1;
            matSum += sum;
        }
        if( matSum > ans )
            ans = matSum;
    }
    fout<<ans;


return 0;
}