#include <bits/stdc++.h>
using namespace std;
ifstream f("flip.in");
ofstream g("flip.out");
bitset <17> op;
int a[17][17];
int n, m, i, j;
int backtraking(int k)
{
    if(k == m + 1)
    {
        int sum = 0;
        for(int i = 1;i <= n;i++)
        {
            int s = 0;
            for(int j = 1;j <= m;j++)
                if(op[j]) s += -a[i][j];
                else s += a[i][j];
            if(s < 0) sum += -s;
            else sum += s;
        }
        return sum;
    }
    op[k] = 0;
    int a1 = backtraking(k + 1);
    op[k] = 1;
    int a2 = backtraking(k + 1);
    return max(a1, a2);
}
int main()
{
    f >> n >> m;
    for(i = 1;i <= n;i++)
        for(j = 1;j <= m;j++) f >> a[i][j];
    g << backtraking(1);
}