#include <bits/stdc++.h> //JuniorMonster a.k.a Sho10
#define ll long long int
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#define all(a) (a).begin(), (a).end()
#define sz size
#define f first
#define s second
#define pb push_back
#define er erase
#define in insert
#define mp make_pair
#define pi pair
#define rc(s) return cout<<s,0
#define mod 1000000007
#define PI 3.14159265359
#define CODE_START  ios_base::sync_with_stdio(false);cin.tie(0);cerr.tie(0);cout.tie(0);
using namespace std;
ll n,m,a[20][20],b[20],s1,s,ans=INT_MIN,x;
int32_t main(){
CODE_START;
ifstream cin("flip.in");
ofstream cout("flip.out");
cin>>n>>m;
for(ll i=1;i<=n;i++)
    for(ll j=1;j<=m;j++)
    cin>>a[i][j];
while(b[0]==0){
    s1=0;
    for(ll i=1;i<=n;i++)
    {
        s=0;
        for(ll j=1;j<=m;j++)
        if(b[j]==1){
            s=s-a[i][j];
        }else s=s+a[i][j];
        if(s<=0){
            s1=s1-s;
        }else s1=s1+s;
    }
    ans=max(ans,s1);
    x=m;
    for(x=m;b[x]==1;x--)
        b[x]=0;
    b[x]++;
}
cout<<ans<<endl;
}