#include <bits/stdc++.h>

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

#define ll long long
#define ld long double

using namespace std;
using namespace __gnu_pbds;

typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;

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

const int NMAX = 16;

int n, m, answer;
int a[NMAX + 1][NMAX + 1];

void flip_row(int i) {
    for(int j = 1; j <= m; j++) {
        a[i][j] = -a[i][j];
    }
}

int get_max_sum() {
    int answer = 0;
    for(int j = 1; j <= m; j++) {
        int sum1 = 0, sum2 = 0;
        for(int i = 1; i <= n; i++) {
            sum1 += a[i][j];
            sum2 += -a[i][j];
        }
        answer += max(sum1, sum2);
    }
    return answer;
}

int main() {
    fin >> n >> m;
    for(int i = 1; i <= n; i++) {
        for(int j = 1; j <= m; j++) {
            fin >> a[i][j];
        }
    }

    for(int mask = 0; mask < (1 << n); mask++) {
        for(int i = 1; i <= n; i++) {
            if(mask >> (i - 1) & 1) {
                flip_row(i);
            }
        }
        answer = max(answer, get_max_sum());
        for(int i = 1; i <= n; i++) {
            if(mask >> (i - 1) & 1) {
                flip_row(i);
            }
        }
    }
    fout << answer << '\n';
    return 0;
}