#include <iostream>
#include <cstdio>
#include <climits>

using namespace std;
int n,m,a[20][20],b[20],sol=INT_MIN;
void sum()
{
    int ln,nn,rf=0;
    for(int i=0;i<n;i++)
    {
        ln=nn=0;
        for(int j=0;j<m;j++)
        {
            if(b[j]==0)
            {
                ln+=a[i][j];
                nn-=a[i][j];
            }
            else
            {
                ln-=a[i][j];
                nn+=a[i][j];
            }
        }
        rf+=max(ln,nn);
    }
    sol=max(rf,sol);
}
void solve()
{
    int i;
    while(b[0]==0)
    {
        i=m-1;
        while(b[i]==1 && i>-1)
            b[i--]=0;
        b[i]=1;
        sum();
    }
}
int main()
{
    freopen("flip.in","r",stdin);
    freopen("flip.out","w",stdout);
    scanf("%d %d", &n, &m);
    for(int i=0;i<n;i++)
    {
        scanf("\n%d", &a[i][0]);
        for(int j=1;j<m;j++)
        {
            scanf(" %d", &a[i][j]);
        }
    }
    solve();
    cout<<sol;
    return 0;
}