#include <bits/stdc++.h>
#define N 17
using namespace std;
ifstream in("flip.in");
ofstream out("flip.out");
int a[N][N],sgn[N],n,m,ms=-(1<<29),s,x=1;
void bk(){
    int i,j,t;
    if(x==m+1){
        s=0;
        for(i=1; i<=n; ++i){
            t=0;
            for(j=1; j<=m; ++j)
                t+=a[i][j]*sgn[j];
            s+=max(t,-t);
        }
        ms=max(ms,s);
        return;
    }
    sgn[x++]=1;
    bk();
    sgn[x-1]=-1;
    bk();
    --x;
}
int main(){
    int i,j;
    in>>n>>m;
    for(i=1; i<=n; ++i)
        for(j=1; j<=m; ++j)
            in>>a[i][j];
    bk();
    out<<ms;
    return 0;
}