#include <iostream>
#include <fstream>

using namespace std;
ifstream in("flip.in");
ofstream out("flip.out");
int M[17][17],n,m;
void citire()
{
    in>>n>>m;
        for(int i=1;i<=n;++i)
            for(int j=1;j<=m;++j)
                in>>M[i][j];
}
int Sumacandschimbielx(int x,int y){

int S=0;
    for(int i=1;i<=n;++i){
        M[i][y]*=-1;
       }
    for(int j=1; j<=m; ++j){
        M[x][j]*=-1;
    }
        for(int i=1;i<=n;++i)
            for(int j=1;j<=m;++j)
                S+=M[i][j];

    for(int i=1;i<=n;++i){
        M[i][y]*=-1;
       }
    for(int j=1; j<=m; ++j){
        M[x][j]*=-1;
    }
    return S;

    }
int afisare()
{
    int maxim=0;
    for(int i=1;i<=n;++i)
        for(int j=1;j<=m;++j)
        if(Sumacandschimbielx(i,j)>maxim)
            maxim=Sumacandschimbielx(i,j);
    out<<maxim;
}
int main()
{
    citire();
    afisare();
    return 0;
}