#include <bits/stdc++.h>

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

int a[20][20],b[20],n,m;
int main()
{
    int s1,s,smax,i,j;
    smax=INT_MIN;
    fin>>n>>m;
    for(i=1;i<=n;i++)
        for(j=1;j<=m;j++)fin>>a[i][j];
    while(b[0]==0)
    {
        s1=0;
        for(i=1;i<=n;i++)
        {
            s=0;
            for(j=1;j<=m;j++)
                if(b[j]==1)
                s-=a[i][j];
            else s+=a[i][j];
            if(s<0)s=-s;
            s1+=s;
        }
        smax=max(smax,s1);
        for(i=m;b[i]==1;i--)
            b[i]=0;
        b[i]=1;
    }
    fout<<smax;
    return 0;
}