#include <fstream>
#include <cmath>
using namespace std;
ifstream fin("flip.in");
ofstream fout("flip.out");
int n,m,a[20][20],semn[20],i,j,sol;
void bt(int pas) {
	if (pas==m+1) {
		int sum=0;
		for (int i=1;i<=n;i++) {
			int sumalinie=0;
			for (int j=1;j<=m;j++)
				sumalinie+=a[i][j]*semn[j];
			sum+=abs(sumalinie);
		}
		sol=max(sol,sum);
		return;
	}
	semn[pas]=1; bt(pas+1);
	semn[pas]=-1; bt(pas+1);
}
int main() {
	fin>>n>>m;
	for (i=1;i<=n;i++)
		for (j=1;j<=m;j++) {
			fin>>a[i][j];
			sol+=a[i][j];
		}
	semn[1]=1;
	bt(2);
	fout<<sol;
	return 0;
}