#include <bits/stdc++.h>

using namespace std;
int n,m;
int ans=-17*17*int(1e6);
int A[17][17],B[17]={0};
static inline void change(int row){
for(int j=1;j<=m;++j)
    A[row][j]*=-1,B[j]+=2*A[row][j];
}
static inline void update_max(){
int curr_sum=0;
for(int i=1;i<=m;++i)
    curr_sum+=(B[i]>=0?B[i]:-B[i]);
ans=max(ans,curr_sum);
}
static inline void back_tr(int curr_row=1){
if(curr_row==n){
    update_max();
    return;
}
back_tr(curr_row+1);
change(curr_row);
back_tr(curr_row+1);
}
int main()
{
    freopen("flip.in","r",stdin);
    freopen("flip.out","w",stdout);
    scanf("%d %d ",&n,&m);
    for(int i=1;i<=n;++i)
        for(int j=1;j<=m;++j)
            scanf("%d ",&A[i][j]),B[j]+=A[i][j];
    back_tr();
    printf("%d ",ans);
}