#include<cstdio>
int a[20][20],b[20];
int main(void){
    freopen("flip.in","r",stdin);
    freopen("flip.out","w",stdout);
    int n,m,aux,i,j,s,max1=0,s1,k;
    scanf("%d %d\n",&n,&m);
    for(i=1;i<=n;++i)
      for(j=1;j<=m;++j)
        scanf("%d ",&a[i][j]);
    for(i=1;i<(1<<m);++i){
                 aux=i; s=0;
                 for(j=1;j<=m;++j)
                 {
                 b[j]=aux&1;
                 aux>>=1;
                 }
                 for(k=1;k<=n;++k){
                 s1=0;
                    for(j=1;j<=m;++j)(b[j])?(s1+=a[k][j]):(s1-=a[k][j]);
                 if(s1<0)s-=s1; else s+=s1;
                   }
                   if(s>max1)max1=s;
                          }
    printf("%d",max1);
 return 0;
}