#include <iostream>
#include <fstream>

using namespace std;

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

int matr[17][17], n, m;
int sumMax;
int operatie[47], sol[17];

void citire(){
    in >> n >> m;
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= m; j++){
            in >> matr[i][j];
            sumMax = sumMax + matr[i][j];
        }
    }
    in.close();
}

void initializareOperatie(){
    for(int i = 1; i <= m; i++){
        operatie[i] = 1;
    }
}

int maxim(int a, int b){
    if(a > b){
        return a;
    }
    return b;
}

void bkt(int varf){
    for(int i = sol[varf - 1] + 1; i <= m; i++){
        sol[varf] = i;
        operatie[i] = -1;
        int sumTemp = 0;
        for(int lin = 1; lin <= n; lin++){
            int sumLinPlus = 0, sumLinMinus = 0;
            for(int col = 1; col <= m; col++){
                sumLinMinus = sumLinMinus - operatie[col] * matr[lin][col];
                sumLinPlus = sumLinPlus + operatie[col] * matr[lin][col];
            }
            sumTemp = sumTemp + maxim(sumLinPlus, sumLinMinus);
        }
        if(sumTemp )
        if(sumTemp > sumMax){
            sumMax = sumTemp;
        }
        if(varf < m){
            bkt(varf + 1);
        }
        operatie[i] = 1;
    }
}

int main() {
    citire();
    initializareOperatie();
    bkt(1);
    out << sumMax;
    return 0;
}