#include <fstream>

using namespace std;

ifstream fin( "flip.in" );
ofstream fout( "flip.out" );

const int DIM = 18;

int t[DIM][DIM];
int n, m, res = -1e9;

void solve( int line ) {
  if ( line == n ) {
	int s = 0;
	for ( int j = 0; j < m; ++j ) {
	  int sp = 0;
	  for ( int i = 0; i < n; ++i ) {
		sp += t[i][j];
	  }
	  s += abs(sp);
	}
	res = max(res, s);
	return;
  }
  solve( line + 1 );
  for ( int j = 0; j < m; ++j ) {
	t[line][j] = -t[line][j];
  }
  solve( line + 1 );
  for ( int j = 0; j < m; ++j ) {
	t[line][j] = -t[line][j];
  }
}

int main() {
  fin >> n >> m;
  for ( int i = 0; i < n; ++i ) {
	for ( int j = 0; j < m; ++j ) {
      fin >> t[i][j];
	}
  }
  solve(0);
  fout << res;
  fin.close();
  fout.close();
  return 0;
}