#include <iostream>
#include <fstream>
using namespace std;

fstream f("flip.in", ios::in);
fstream g("flip.out", ios::out);
int v[17],n,m;
long long maxi;
int main()
{ f >> n >> m;
    int a[n+1][m+1];
    for(int i =1; i <= n; i++)
    {
        for(int j = 1; j <= m; j++)
        {
            f >> a[i][j];
            maxi= maxi + a[i][j];
        }
    }
    while(v[0] == 0)
    {
       int a1 = m;
        while(v[a1]==1)
        {
            v[a1]=0;
            a1--;
        }
        v[a1]=1;
        long long  s = 0;
        for(int i = 1; i <= n; i++)
        {
           long long  s2 = 0;
            for(int j = 1; j <= m; j++)
            {
                if(v[j] == 1)
                {
                    s2 -= a[i][j];
                }
                else
                {
                    s2 += a[i][j];
                }
            }
            if(s2 < 0)
            {
                s2 *=(-1);
            }
            s = s + s2;
        }
        if(s > maxi)
        {
            maxi = s;
        }
    }
    g<<maxi<<"\n";
    return 0;
}