#include <bits/stdc++.h>
using namespace std;
ifstream fin("flip.in");
ofstream fout("flip.out");

int T[20][20],N,M,Sol,sum,total;

int main()
{
    fin >> N >> M;
    Sol = -1000000;

     for (int i = 1;i <= N ;i++)
        for (int j = 1;j <= M;j++) fin >> T[i][j];

     for (int k = 0;k <= (1 << M);k++)
     {
         total = 0;
         for (int i = 1;i <= N ;i++)
         {
             sum = 0;
             for (int j = 1;j <= M;j++)
                if((k >> (j-1)) & 1)
                   sum += T[i][j]*(-1);
                else
                   sum += T[i][j];
             if (sum < 0 ) sum *= -1;
             total += sum;
         }
         if (total > Sol) Sol = total;
      }

    fout << Sol;

    return 0;
}