#include <bits/stdc++.h>
using namespace std;

int n, m, v[20][20], ans = INT_MIN, sum, slin, col[20], T;

int main(){
	ifstream cin("flip.in");
	ofstream cout("flip.out");

	cin >> n >> m;
	for(int i = 1; i <= n; ++i)
		for(int j = 1; j <= m; ++j)
			cin >> v[i][j];
	int c = 1 << m;
	for(int i = 0; i < c; ++i){
		memset(col, 0, sizeof col);
		for(int i2 = 0; i2 < i; ++i2)
			if((i >> i2) & 1)
				col[i2 + 1] = 1;
		sum = 0;
		for(int x = 1; x <= n; ++x){
			slin = 0;
			for(int y = 1; y <= m; ++y){
				T = v[x][y];
				if(col[y])
					T = -T;
				slin += T;
			}
			sum += abs(slin);
		}
		ans = max(ans, sum);
	}
	cout << ans;
}