#include <bits/stdc++.h>
using namespace std;
ifstream fin("flip.in");
ofstream fout("flip.out");
int n,m,sum,s,maxim,v[1002],a[20][20],i,j;
int main()
{fin>>n>>m;
for(i=1;i<=n;i++)
    for(j=1;j<=m;j++)fin>>a[i][j];
while(v[0]==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;
}