#include <iostream> 
#include <stdio.h>
#include <math.h>
using namespace std ;

int v[17][17];
int n, m;

void citire(){
	freopen("flip.in","r",stdin);
	cin >> n >> m ;	
	for (int i = 0 ; i < n ; i++)
		for (int j = 0 ; j < m ; j++)
			cin >> v[i][j] ;
}

int main(){
	
	int max = 0, sum, s, sfarsit, lini[17] , k ;	
	citire();

	sfarsit = pow(2,n) ;
	for (int i,j,l= 0; l < sfarsit ; l++){		
		k = l ;
		for (j = 0 ; j < n ; j++) {
			lini[j] = k % 2 == 0 ? 1 : -1 ;
			k = k / 2 ;
		}
		sum = 0 ;
		for (i = 0 ; i < n ; i++){
			s = 0 ;
			for ( j = 0 ; j < m ; j++)
				s+= v[i][j]*lini[j];
			if (s < 0) {sum -=s ;}
			else {sum +=s;}
		}
		if (max < sum) max = sum ;
	}
	freopen("flip.out","w",stdout);
	cout << max ;
	return 0  ;
}