#include <fstream>
using namespace std;

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

int n,m,i,j,v[17][17],a[17][17],col[17],s,S,M;

int main(){
    fin>>n>>m;
    for(i=1;i<=n;i++)
        for(j=1;j<=m;j++)
            fin>>v[i][j];


    while(col[0]==0){
            i=m;
            while(col[i]==1){
                col[i]=0;
                i--;
            }
            col[i]=1;

            S=0;
            for(i=1;i<=n;i++){
                s=0;
                for(j=1;j<=m;j++){
                    if(col[j]==0)
                        s+=v[i][j];
                    else
                        s-=v[i][j];
                }
                if(s<0)
                    S-=s;
                else
                    S+=s;
            }
            if(S>M)
                M=S;
    }

    fout<<M;

    return 0;
}