#include <bits/stdc++.h>
#define NMAX 20

using namespace std;

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

int v[NMAX][NMAX];
int n, m;
int lnsum1[NMAX], colsum1[NMAX];
int lnsum2[NMAX], colsum2[NMAX];

void prelucrare() {
    int i = 1;
    while (i <= n) {
        if (lnsum1[i] < lnsum2[i]) {
            for (int j = 1; j <= m; j++)
                v[i][j] *= -1;
        }
        i++;
    }
    i = 1;
    while (i <= m) {
        if (colsum1[i] < colsum2[i]) {
            for (int j = 1; j <= n; j++)
                v[j][i] *= -1;
        }
        i++;
    }
}

int suma () {
    int s = 0;
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++)
            s += v[i][j];
    return s;
}

void afisare () {
    for (int i = 1; i <= n; i ++)
        cout << lnsum1[i] << endl;
    cout << endl;
    for (int i = 1; i <= n; i++)
        cout << lnsum2[i] << endl;
    cout << endl;
    for (int i = 1; i <= m; i++)
        cout << colsum1[i] << ' ';
    cout << endl;
    for (int i = 1; i <= m; i++)
        cout << colsum2[i] << " ";
}

void afisare1 () {
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++)
            cout << v[i][j] << ' ';
        cout << endl;
    }
}

int main()
{
    fin >> n >> m;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            fin >> v[i][j];
            lnsum1[i] += v[i][j];
            colsum1[j] += v[i][j];
            lnsum2[i] += (v[i][j] * (-1));
            colsum2[j] += (v[i][j] * (-1));
        }
    }
    prelucrare();
    fout << suma();
}