#include <stdio.h>
#include <stdlib.h>
 
int N,M;
int mat[17][17];
 
FILE *f, *g;
 
void readData()
{
    f = fopen("flip.in","r");
    g = fopen("flip.out","w");
     
    fscanf(f,"%d %d\n",&N,&M);
    int i,j;
    for(i = 0; i < N; ++i)
        for(j = 0; j < M; ++j)
            fscanf(f,"%d",&mat[i][j]);
         
    fclose(f);
    return;
}
 
int main()
{
    readData();
     
    int activeRow = 0;
    int activeCol = 0;
    int i = 0;
    int j = 0;
     
    int sum = 0;
    int max = 0x80000000;
     
    for(activeRow = 0; activeRow < 1 << N; ++activeRow)
    {
            sum = 0;
            for(i = 0; i < N; ++i){
		int linie = 0;
                for(j = 0; j < M; ++j)
                {
                    
                    if((1<<j)&activeRow) 
                        linie += -mat[i][j];
                    else
                        linie += mat[i][j];
                     
                }
		if(linie < 0)
			linie = -linie;
	        sum+=linie;
	    }
           
            if(sum > max)
                max = sum;
    }
    fprintf(g,"%d\n",max);
    fclose(g);
    return 0;
}