#include <iostream>
#include <fstream>

using namespace std;

ifstream fi("flip.in");
ofstream fo("flip.out");

int main()
{
    int n, m, a[1000][1000], b[1000][100];
    
    fi>>n>>m;
    
    for(int i = 0; i < n; i++)
        for (int j = 0; j < m; j++)
        {
            fi>>a[i][j];
            b[i][j] = a[i][j];
        }
    
    int s_1 = 0;
    
    for(int i = 0; i < n; i++)
    {
        int s_local_1 = 0, s_local_2 = 0;
        
        for (int j = 0; j < m; j++)
        {
            s_local_1 += a[i][j];
        }
        
        for (int j = 0; j < m; j++)
        {
            s_local_2 = s_local_2 + (a[i][j]*(-1));
        }
        
        if (s_local_1 < s_local_2)
        {
            for (int j = 0; j < m; j++)
                a[i][j] *= -1;
        }
    }
    
    for(int i = 0; i < m; i++)
    {
        int s_local_1 = 0, s_local_2 = 0;
        
        for (int j = 0; j < n; j++)
        {
            for (int j = 0; j < n; j++)
            {
                s_local_1 += a[j][i];
            }
            
            for (int j = 0; j < n; j++)
            {
                s_local_2 = s_local_2 + (a[j][i]*(-1));
            }
            
            if (s_local_1 < s_local_2)
            {
                for (int j = 0; j < n; j++)
                    a[j][i] *= -1;
            }

            
        }
    }
    
    for(int i = 0; i < n; i++)
        for (int j = 0; j < m; j++)
            s_1 += a[i][j];
 
    
////////////////////////
    
    
    
    int s_2 = 0;
    
    for(int i = 0; i < m; i++)
    {
        int s_local_1 = 0, s_local_2 = 0;
        
        for (int j = 0; j < n; j++)
        {
            for (int j = 0; j < n; j++)
            {
                s_local_1 += a[j][i];
            }
            
            for (int j = 0; j < n; j++)
            {
                s_local_2 = s_local_2 + (a[j][i]*(-1));
            }
            
            if (s_local_1 < s_local_2)
            {
                for (int j = 0; j < n; j++)
                    a[j][i] *= -1;
            }
            
            
        }
    }
    
    
    for(int i = 0; i < n; i++)
    {
        int s_local_1 = 0, s_local_2 = 0;
        
        for (int j = 0; j < m; j++)
        {
            s_local_1 += a[i][j];
        }
        
        for (int j = 0; j < m; j++)
        {
            s_local_2 = s_local_2 + (a[i][j]*(-1));
        }
        
        if (s_local_1 < s_local_2)
        {
            for (int j = 0; j < m; j++)
                a[i][j] *= -1;
        }
    }
    

    
    for(int i = 0; i < n; i++)
        for (int j = 0; j < m; j++)
            s_2 += a[i][j];
    
    if(s_1 > s_2)
        fo<<s_1;
    else
        fo<<s_2;
    
    fo.close();
    return 0;
}