/******************************************************************************

                              Online C++ Compiler.
               Code, Compile, Run and Debug C++ program online.
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*******************************************************************************/

#include <bits/stdc++.h>
#define int long long
#pragma GCC optimize ("O3")
#define pb push_back
using namespace std;

int n, m;
const int nmax=20;
vector <vector <int>> a(nmax, vector <int>(nmax, 0));

int backtracker(int n, int path, int lim){
    if(n == lim + 1){
        int ff=0;
        for(int j=1;j <= m;j++){
            int ss=0;
            for(int i=1;i <= n;i++)ss+=a[i][j];
            ff += abs(ss);
        }
        return ff;
    }
    if(n != 0){
        if(path == 1){
            for(int i=1;i <= m;i++)a[n][i] *= -1;
        }    
    }
    return max(backtracker(n + 1, 0, lim), backtracker(n + 1, 1, lim));
}

signed main(){
    ifstream cin ("flip.in");
    ofstream cout ("flip.out");
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    
    cin >> n >> m;
    for(int i=1;i <= n;i++){
        for(int j=1;j <= m;j++){
            cin >> a[i][j];
        }
    }
    
    cout << backtracker(0, 0, n + 1);
    return 0;
}