#include "stdio.h"

int main(){
	
	int n,m;
	int i,j;
	int mat[16][16];
	int sumR[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
	int sumC[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
	int sum = 0;
	FILE *fptr;
	fptr = fopen("flip.in", "r");
	fscanf(fptr,"%d",&n);
	fscanf(fptr,"%d",&m);
	for(i = 0; i < n ; i++){
		for(j = 0;j < m ; j++){
			fscanf(fptr,"%d",&mat[i][j]);
		}
	}
	
	for(i = 0;i < n; i++){
		for(j = 0;j < m; j++){
			sumR[i] = sumR[i] + mat[i][j];
			sumC[j] = sumC[j] + mat[i][j];
		}
	}
	
	for(i = 0; i<n;i++){
		if(sumR[i] < 0){
			for(j=0;j<m;j++){
				sumC[j] = sumC[j] - 2 * mat[i][j];
				mat[i][j] = (-1) * mat[i][j];
			}
		}
	}
	
	for(i=0;i<m;i++){
		if(sumC[i] < 0){
			sum = sum - sumC[i];
		}
		else{
			sum = sum + sumC[i];
		}
	}
	
	fclose(fptr);
	fptr = fopen("flip.out", "w");
	fprintf(fptr,"%d\n",sum);
	
	return 0;
}