#include <iostream>
#include <fstream>

using namespace std;

ifstream f("flip.in");
ofstream g("flip.out");

int n,m,matrix[20][20],sign[20],Max;

int solve(){
    int answer = 0;
    for(int j = 1;j <= m;j++){
        int s = 0;
        for(int i = 1;i <= n;i++)
            s += matrix[i][j] * sign[i];
        answer += abs(s);
    }
    return answer;
}

void Back(int k){
    if(k == n + 1){
        Max = max(Max,solve());
    }else{
        sign[k] = 1;
        Back(k + 1);
        sign[k] = -1;
        Back(k + 1);
    }
}

int main(){
    f >> n >> m;
    for(int i = 1;i <= n;i++)
        for(int j = 1;j <= m;j++)
            f >> matrix[i][j];
    Back(1);
    g << Max;
}