#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 < m; ++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;

}