#include<bits/stdc++.h>
using namespace std;
ifstream in("flip.in");
ofstream out("flip.out");
typedef long long ll;

int col[18],v[18][18];
ll cnt=0,n,m;

void dfs(ll k){
ll sum=0;
 for(int i=1;i<=m;++i){
    sum+=abs(col[i]);
 }
 cnt=max(cnt,sum);
 for(int i=k+1;i<=n;++i){
    for(int j=1;j<=m;++j){
        col[j]+=-2*v[i][j];
    }
    dfs(i);
    for(int j=1;j<=m;++j){
        col[j]+=2*v[i][j];
    }
 }


}


int main()
{
    cin.tie(0);
    ios_base::sync_with_stdio(0);
    cout.tie(0);


    in>>n>>m;
    for(int i=1;i<=n;++i){
        for(int j=1;j<=m;++j){
            in>>v[i][j];
            col[j]+=v[i][j];
        }
    }
    dfs(0);
    out<<cnt<<'\n';


    return 0;
}