#include <bits/stdc++.h>

using namespace std;
ifstream fin ("flip.in");
ofstream fout ("flip.out");
int n,m,i,j,maxim=-1000005,sum,a[20][20],v[20],s;
int main()
{
    fin>>n>>m;
    for (i=1;i<=n;i++)
        for (j=1;j<=m;j++)
            fin>>a[i][j];
    while (v[1]==0)
    {
        j=m;
        while (v[j]==1)
            v[j]=0, j--;
        v[j]=1;
        sum=0;
        for (i=1;i<=n;i++)
            {
                s=0;
                for (j=1;j<=m;j++)
                    if (v[j]==0)
                        s+=a[i][j];
                    else s-=a[i][j];
                if (s>0) sum+=s;
                else sum -=s;
            }
            if (sum>maxim) maxim=sum;
    }
    fout<<maxim;
    return 0;
}