#include <iostream>
#include <cstdio>
#include <climits>
#define inf INT_MIN

using namespace std;
int n, m, MAX=inf, i, a[17][17], j;
int st[17];

long suma()
{
    long sum=0, sum_temp;
    for(int i=1;i<=n;i++)
    {
        sum_temp=0;
        for(int j=1;j<=m;j++)
            if(st[j])
                sum_temp+=a[i][j];
            else sum_temp-=a[i][j];

        if(sum_temp>-sum_temp)
            sum+=sum_temp;
        else sum-=sum_temp;
    }

    return sum;
}

void back(int k)
{
    for(int i=0;i<=1;i++)
    {
        st[k]=i;
        if(k==m)
        {
            long x=suma();
            if(x>MAX)
                MAX=x;
        }
        else
            back(k+1);
    }
}

int main()
{
    freopen("flip.in", "r", stdin);
    freopen("flip.out", "w", stdout);
    scanf("%d %d", &n, &m);

    for(i=1;i<=n;i++)
        for(j=1;j<=m;j++)
            scanf("%d", &a[i][j]);

    back(1);

    printf("%d\n", MAX);
    return 0;
}