#include "fstream"

using namespace std;
int n,m;
int **p;
int *v;
int maxMat=0;

int sum();
void backtrack(int k);
int main(){

    ifstream in;
    in.open("flip.in");

    in>>n>>m;

    p=new int*[n];

    for(int i=0;i<n;i++){ //citire
        p[i]=new int[m];
        for(int j=0;j<m;j++){
            in>>p[i][j];
        }
    }

    in.close();

    v=new int[m];

    backtrack(0);

    ofstream off;
    off.open("flip.out");
    off<<maxMat;

    off.close();

    return 0;
}

void backtrack(int k){

    if(k==m){
        int s1=sum();
        if(maxMat<s1){
            maxMat=s1;
        }
    }else{
        v[k]=1;
        for(int i=0;i<=1;i++){
            v[k]*=-1;
            backtrack(k+1);
        }
    }
}

int sum(){
    int sum=0;
    for(int i=0;i<n;i++){
        int aux=0;
        for(int j=0;j<m;j++){
            aux+=p[i][j]*v[j];
        }
        if(aux<0){
            aux*=-1;
        }
        sum+=aux;
    }
    return sum;
}