#include <iostream>
#include <algorithm>
#include <vector>
#include <stack>
#include <string>
#include <cmath>
#include <map>
#include <fstream>
#include <set>
#include <deque>

#define pb push_back
#define FOR(I,A,B) for(int I=(A); I < (B); I++)
#define MAX 17

using namespace std;

int n, m;
int T[MAX][MAX];
int sol[MAX];
int ans = 0;

ifstream f("flip.in");
ofstream g("flip.out");

int sum() {
	int s = 0;
	FOR(i,0,n) {
		int slin = 0;
		FOR(j,0,m) slin += sol[j] * T[i][j];
		s += abs(slin);
	}
	return s;
}

void back_rec(int k) {
	if(k == m) {
		ans = max(ans, sum());
		return;
	}

	sol[k] = 1; back_rec(k+1);
	sol[k] = -1; back_rec(k+1);
}

void back_it() {
	int k = 0;
	while(k >= 0) {
		if(k == m) ans = max(ans, sum());
		if(sol[k] == 0) sol[k] = 1, k += (k < m);
		else if(sol[k] == 1) sol[k] = -1 , k += (k < m);
		else if(sol[k] == -1) sol[k--] = 0;
	}
}

int main() {
	f >> n >> m;

	FOR(i,0,n) FOR(j,0,m) f >> T[i][j];

	back_it();

	g << ans;

	return 0;
}