# include <fstream.h>
ifstream f ("flip.in"); ofstream g ("flip.out");

int n, m, i, j, sf = 0, v [ 10001 ], a[ 16 ][ 16 ];

void bestsum ( ){
	int i, j, sc = 0, st = 0;
	for ( i = 1; i <= n; i++ ){
		sc = 0;
		for ( j = 1; j <= m; j++ ) sc += ( a[ i ][ j ] * v[ j ] ); // inmultim cu posibilitatea Vj
		if ( sc < 0 ) sc = sc * -1; // daca Vj este -1, flipam linia/coloana
		st += sc;
	}
	if ( sf < st ) sf = st;
}

void backtrack ( int k ){
	if ( k > n ) bestsum ( ); // atunci cand am trecut prin toate posibilitatile si avem construit vectorul V
	else{
		for ( int i = -1; i <= 1; i += 2 ){
			v[k] = i; // vectorul de posibilitati/pozitii/combinari 
			backtrack ( k + 1 ); // apelare recurenta
		}
	}
}

int main(){
	f >> n >> m;
	for ( i = 1; i <= n; i++ ) for ( j = 1; j <= m; j++ ) f >> a[i][j];
	backtrack ( 1 ); // dam valoarea variabilei k = 1 pentru a incepe subprogramul backtrack 
	g << sf;
	g.close();
	return 0;
}