#include <fstream>
using namespace std;
ifstream fin("flip.in");
ofstream fout("flip.out");
int n,m,i,j,s,sum,maxi,a[17][17],v[17];
int main() {
    fin>>n>>m;
    for (i=1;i<=n;i++)
        for (j=1;j<=m;j++)
            fin>>a[i][j];
    while (v[1]==0) {
        i=m;
        while (v[i]==1)
            v[i--]=0;
        v[i]=1;
        sum=0;
        for (i=1;i<=n;i++) {
            s=0;
            for (j=1;j<=m;j++)
                if (v[j]==0)
                    s+=a[i][j];
                else
                    s-=a[i][j];
            if (s>0)
                sum+=s;
            else
                sum-=s;
        }
        if (sum>maxi)
            maxi=sum;
    }
    fout<<maxi;
    return 0;
}