#include<stdio.h>
int N,M;


int bkt(int sum_row[N], int sum_col[M], int sum_matrix, int max){
	int i,j, max_bkt;
	
	for(i=0; i<N; i++)
	//	if(sum_row[i] < 0)
			if(sum_matrix - 2*sum_row[i] > max){
				sum_row[i] *= -1;
				int sum = sum_matrix + 2 * sum_row[i];
				max_bkt = bkt(sum_row, sum_col, sum, sum);
				sum_row[i] *= -1;
				if(max_bkt > max)
					max = max_bkt;
			}

					
	for(j=0; j<M; j++)
	//	if(sum_col[j] < 0)
			if(sum_matrix - 2*sum_col[j] > max){
				sum_col[j] *= -1;
				int sum = sum_matrix + 2 * sum_col[j];
				max_bkt = bkt(sum_row, sum_col, sum, sum);
				sum_col[j] *= -1;
				if(max_bkt > max)
					max = max_bkt;
			}
			
	return max;

}

int main(char *argv[]){
	
	FILE *f = fopen("flip.in", "rt");
	int i,j;
	fscanf(f, "%d %d", &N, &M);
	
	int a[N][M], sum_row[N], sum_col[M], sum_matrix = 0, max;
	for(i=0; i<N; i++)
		sum_row[i] = 0;
	
	for(i=0; i<M; i++)
		sum_col[i] = 0;
	
	for(i=0; i<N; i++)
		for(j=0; j<M; j++){
				fscanf(f,"%d", &a[i][j]);
				sum_row[i] += a[i][j];
				sum_col[j] += a[i][j];
				sum_matrix += a[i][j];
		}
		
	max = sum_matrix;
	max = bkt(sum_row, sum_col, sum_matrix, max);	

	FILE *fout = fopen("flip.out", "wt");
	fprintf(fout, "%d", max);
	
	fclose(f);
	fclose(fout);
	
	return 0;
}