#include <stdio.h>
#include<math.h>

#define MAX 20

int l,c,i,j;
int SUM=0;
int mat[MAX][MAX];
int com[MAX];
int necom[MAX];
int sum1[MAX];
int sum2[MAX];

void citire_matrice(){
    FILE* f =fopen("flip.in", "rt");
    fscanf(f, "%d %d",&c,&l);
    for(i=0;i<l;++i)
        for(j=0;j<c;++j)
            fscanf(f,"%d",&mat[i][j]);
fclose(f);
}

void suma(){

    for (i=0;i<l;++i){
        for(j=0;j<c;++j){
            necom[i]+=mat[i][j];
            com[i]+=(-1)*mat[i][j];
        }
        if(necom[i]<com[i]){
            for (j=0;j<c;++j)
                mat[i][j]=-mat[i][j];
        }
    }
        for (j=0;j<c;++j){
            for(i=0;i<l;i++){
                sum1[j]+=mat[i][j];
                sum2[j]=(-1)*mat[i][j];
            }
            if (sum1[j]<sum2[j])
            sum1[j]=sum2[j];

        SUM+=sum1[j];
    }
}

void scriere_matrice(){
FILE*g=fopen("flip.out","wt");
fprintf(g,"%d",SUM);
fclose(g);
}

int main(){
citire_matrice();
suma();
//printf("%d",SUM);
scriere_matrice();
return 0;
}