#include <stdio.h>
#include <stdlib.h>

int main()
{
    int a[10][10];
    int i,j,m,n;
    FILE *pf,*pfi;
   pf= fopen("flip.in","r");
   pfi=fopen("flip.out","w");

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

 int sum=0,k=0,p=0;

for(i=0;i<n;i++)
    for(j=0;j<m;j++)
{
    fscanf(pf,"%d",&a[i][j]);
    k=k+a[i][j];
    p=p+(a[i][j]*(-1));
    if(k<=p){
        sum=sum+p;}
    else{ sum=sum+k;}
    }
fprintf(pfi,"%d",sum);
return 0;

}