#include<stdio.h>
#include<stdlib.h>
#include<math.h>
#include<string.h>
int b[1000];

void baza(int i)
{
	int k=0;
	while(i)
	{
		b[k++]=i%2;
		i/=2;
	}
	//return k;
}

int main()
{
	
	int n,m,i,j,max=0;
	int a[100],mat[20][20];
	FILE *in=fopen("flip.in","r");
	fscanf(in,"%d%d",&n,&m);
	for (i=0;i<n;++i)
		for (j=0;j<m;++j)
			fscanf(in,"%d",&mat[i][j]);
	
	int mat_t[5][5];
	
	
	int dan,put=(int)pow(2,m),tmp;
	for(i=0;i<put;++i)
	{
		baza(i);
		int s=0;
		memset(a,0,n*sizeof(a[0]));
		for(j=0;j<m;++j)
			if (!b[j]) b[j]=-1;
		//generat vectorul ; ma ocup de pozitii;
		for (dan=0;dan<m;++dan)
		{
			//int s=0,s2=0;
			for (tmp=0;tmp<n;++tmp)
				a[tmp]+=(mat_t[tmp][dan]=mat[tmp][dan]*b[dan]);
			/*
			for (tmp=0;tmp<n;++tmp)
				{
					for (dan=0;dan<m;++dan)
					printf("%d ",mat_t[tmp][dan]);
				printf("\n");
			}
			*/
			/*for (tmp=0;tmp<n;s+=a[tmp++][dan]);
			for (tmp=0;tmp<n;s2+=a[tmp++][dan]*b[dan]);
			printf("s=%d,s2=%d\n",s,s2);
			if (s<s2) 
				{
					for (tmp=0;tmp<n;mat_t[tmp++][dan]=mat[);
						
			*/
			
		}
		for(tmp=0;tmp<n;tmp++)
			if(a[tmp]<0)
				s-=a[tmp];
			else
				s+=a[tmp];
		if(s>max)
			max=s;
		
		//printf("\n");
	}
	fprintf(fopen("flip.out","w"),"%d\n",max);
	return 0;
}