#include <fstream>
std::ifstream cin("flip.in");
std::ofstream cout("flip.out");
#define maxn 20
int v[maxn][maxn],flip[maxn],n,m,best=-55555;

int rasop()
{
    int S=0,s=0;
    for(int i=1;i<=n;i++){ //parcurgerea col
        S=0;
        for(int j=1;j<=m;j++) //parcurgerea liniilor
            if(flip[j])
                S+=(0-v[i][j]);
            else
                S+=v[i][j];
        if(S<0) //daca suma liniei <0 "inmultim" cu -1
            s+=(0-S);
        else
            s+=S;
    }
    return s;

}

int main()
{
    int suma;
    cin>>n>>m;
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++)
            cin>>v[i][j];
    for(int i=1;i<(1<<n);i++){
        for(int j=0;(1<<j)<=i;j++){
            if((1<<j)&i)
                flip[j+1]=1;
            else
                flip[j+1]=0;
        }
        suma=rasop();
        best = (best<suma)?suma:best;
    }
    cout<<best;
    return 0;
}