#include<iostream>
#include<fstream>
using namespace std;
fstream f("flip.in", ios::in);
ofstream g("flip.out", ios::out);
long suma(long A[17][17], int n, int m, int x, int y)
{
	long s=0;
	for(int i=1; i<=n; i++)
		for(int j=1; j<=m; j++)
			if(i==x || j==y)
				s = s + A[i][j]*(-1);
			else
				s = s + A[i][j];
	return s;
}

int main()
{
	int N, M;
	long int A[17][17], sm=-1000000, max=0;
	f>>N>>M;
	for(int i=1; i<=N; i++)
		for(int j=1;j<=M;j++)
			f>>A[i][j];
	f.close();
	for(int i=0; i<=N; i++)
		for(int j=0; j<=M; j++)
		{	
			max = suma(A,N,M,i,j);
			if(sm < max)
				sm = max;
		}
	g<<sm;
	g.close();
}