//
//  main.cpp
//  Flip
//
//  Created by Nagy Dani on 2014.02.27..
//  Copyright (c) 2014 Nagy Dani. All rights reserved.
//

#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <vector>

std::vector<int>sums;
int N,M;
int **mat;

using namespace std;

void beolvas(int &n,int&m, int***a){
    FILE* in = fopen("flip.in","r");
    fscanf(in,"%d %d",&n,&m);
    
    *a = (int**)malloc( (n)*sizeof(int*));
    for(int i=0;i<n;i++){
        *((*a) + i) = (int*)malloc( (m)*sizeof(int) );
        for(int j=0;j<m;j++){
            fscanf(in,"%d",(*((*a)+i)+j) );
        }
    }
}

void negaterow(int i){
    for(int j=0;j<M;j++) mat[i][j] = -1*mat[i][j];
}
void negatecol(int i){
    for(int j=0;j<N;j++) mat[j][i] = -1*mat[j][i];
}
int sumrow(int i){
    int s = 0;
    for(int j=0;j<M;j++) s+= mat[i][j];
    return s;
}
int sumcol(int i){
    int s = 0;
    for(int j=0;j<N;j++) s+= mat[j][i];
    return s;
}
int negsumrow(int i){
    int s = 0;
    for(int j=0;j<M;j++) s+= -mat[i][j];
    return s;
}
int negsumcol(int i){
    int s = 0;
    for(int j=0;j<N;j++) s+= -mat[j][i];
    return s;
}

int sum(){
    int s = 0;
    for(int i = 0;i<N;i++){
        for(int j = 0;j<M;j++){
            s+=mat[i][j];
        }
    }
    return s;
}
int megold(){
    int old = sum();
    //printf("%d",old);
    
    for(int i=0; i< N;i++){
        sums.push_back(old + negsumrow(i));
    }
    
    for(int i=0; i< M;i++){
        sums.push_back(old + negsumcol(i));
    }
    
    for(int i=0; i < N;i++){
        negaterow(i);
        sums.push_back(sum());
    }
    
    for(int i=0; i < N;i++){
        negaterow(i);
        sums.push_back(sum());
    }
    
    for(int i=0; i < M;i++){
        negatecol(i);
        sums.push_back(sum());
    }
    
    for(int i=0; i < M;i++){
        negatecol(i);
        sums.push_back(sum());
    }
    std::vector<int>::iterator it = std::max_element(sums.begin(),sums.end());
    return (*it);
}
int main()
{
    FILE * out  = fopen("flip.out", "w");
    //fprintf(out, "szarik");
    beolvas(N,M,&mat);
    fprintf(out,"%d",megold());
    //printf("%d",556);
    return 0;
}