#include<stdio.h>

long n,m,smax,a[16][16];

int main(){

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

	fscanf(f,"%d%d",&n,&m);

	long i,j,k,s,t;

	for(i=0;i<n;i++) for(j=0;j<m;j++) fscanf(f,"%d",a[i]+j);
	
	for(i = 0; i< ( 1<<m ) ; i++){ s = 0;

		for(j = 0 ; j< n; j++){

			for(t=0,k = 0 ; k < m; k++){

				if( i & (1<<k) ) t += -a[j][k];
				else t+= a[j][k];
			}

			s += t > -t ? t : -t;

		}

		smax = s > smax ? s : smax;
	}

	fprintf(g,"%d",smax);

	return 0;
}