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

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

int n, m, maxim = -1e9, A[20][20];

int main(){
    fin >> n >> m;

    for(int i = 0; i < n; ++i)
        for(int j = 0; j < m; ++j)
            fin >> A[i][j];

    for(int mask = 0; mask < (1 << n); ++mask){
        int sume_col[20] = {0}, suma = 0;
        for(int i = 0; i < n; ++i)
            for(int j = 0; j < m; ++j)
                sume_col[j] += ((mask & (1 << i)) ? (A[i][j]) : (-A[i][j]));

        for(int j = 0; j < m; ++j)
            suma += ((sume_col[j] > 0) ? (sume_col[j]) : (-sume_col[j]));

        maxim = max(maxim, suma);
    }

    fout << maxim;
}