#include <iostream>
#include<cstdio>
#include<cmath>
#define nmax 20
using namespace std;
FILE * f=fopen("flip.in","r");
FILE * g=fopen("flip.out","w");
int n,m,nrmax,v[nmax],c[nmax],b[nmax][nmax],a[nmax][nmax],d[nmax][nmax];
void citire( )
{ int i,j;
    fscanf(f,"%d%d",&n,&m);
for(i=1;i<=n;i++)
{
    for(j=1;j<=m;j++)
    {
        fscanf(f,"%d",&a[i][j]);
    }
}
}
void coloana(int k,int y[nmax][nmax])
{
    for(int i=1;i<=n;i++)
        y[i][k]=-y[i][k];
}
void linie(int k,int y[nmax][nmax])
{
    for(int j=1;j<=m;j++)
        y[k][j]=-y[k][j];
}
int suma(int y[nmax][nmax])
{
    int i,j,s=0,t=0;
    for(i=1;i<=m;i++)
    { s=0;
        for(j=1;j<=n;j++)
        {
            s=s+y[j][i];
        }

        t=t+abs(s);
    }
    return t;
}

void bk(int k)
{ int i,j;
    if(k==n)
    {
for(i=1;i<=n;i++)
{
    for(j=1;j<=m;j++)
    {
        b[i][j]=a[i][j];
    }
}
for(i=1;i<=n;i++)
{
    if(v[i]==1)
        linie(i,b);
}
if(nrmax<suma(b))
    nrmax=suma(b);

    }
    else
    {
        for(i=0;i<=1;i++)
        {
            v[k]=i;
            bk(k+1);
        }
    }
}



int main()
{
    citire( );
    bk(1);
fprintf(g,"%d",nrmax);
    return 0;
}