#include <fstream>
#include <iostream>

using namespace std;

ifstream in("flip.in");
ofstream out("flip.out");

unsigned long int a[16],sum=0,sum1=0,sum2=0,j,i,n,m;

int main()
{

in>>n>>m;
for(i=1;i<=n;i++){
			for(j=1;j<=m;j++) {in>>a[j];
							   sum1+=a[j];
			                   a[j]=a[j]*(-1);
							   sum2+=a[j];}
			if(sum1>=sum2) sum+=sum1;
			           else sum+=sum2;
			sum1=0;
			sum2=0;
                 }
out<<sum;
}