#include<stdio.h>

int v[16][16];

int main()
{
    FILE *f, *g;

    int l,c,SINIT=0;
    int i,j,a;
    int sp=0,sn=0,S1=0,S2=0;

    f=fopen("flip.in","r");
    g=fopen("flip.out","w");

    fscanf(f,"%d%d",&l,&c);

    for(i=0; i<l; i++)
    {
        for(j=0; j<c; j++)
        {
            fscanf(f,"%d",&v[i][j]);
            //printf("%d ",v[i][j]);
            SINIT+=v[i][j];
        }
        //printf("\n");
    }
    if(c<l)
    {
        sp=0;
        sn=0;
        a=0;
        while(a<c)
        {
            sp=0;
            sn=0;
            j=0;
            while(j<l)
            {
                if(v[a][j]>=0)
                    sp+=v[a][j];
                else sn=sn+v[a][j]*-1;
                j++;
            }
            if(sp>sn)
                S1=S1+(sp-sn);
            else S1=S1+(sn-sp);
            a++;
        }
    }
    else
    {
        sp=0;
        sn=0;
        a=0;
        while(a<l)
        {
            sp=0;
            sn=0;
            i=0;
            while(i<c)
            {
                if(v[i][a]>=0)
                    sp+=v[i][a];
                else sn=sn+v[i][a]*-1;
                i++;
            }
            //printf("sn=%d,sp=%d\n",sn,sp);
            if(sp>sn)
                S2=S2+(sp-sn);
            else S2=S2+(sn-sp);
            a++;
        }
    }


    //printf("s1=%d,s2=%d\n",S1,S2);

    if(S1>S2)
        fprintf(g,"%d\n",S1+SINIT);
    else fprintf(g,"%d\n",S2+SINIT);

    fclose(f);
    fclose(g);

    return 0;
}