#include <fstream>
using namespace std;

int main()
{
    ifstream fin("flip.in");
    int n, m;
    fin >> n >> m;
    int a[100][150];
    int i, j;
    int s = 0;
    for ( i = 0; i < n; i++ )
        for ( j = 0; j < m; j++ )
            fin >> a[i][j];
    for ( i = 0; i < n; i++ )
        for ( j = 0; j < n; j++ )
            a[i][j] *= -1;
            s += a[i][j];
        fin.close();
    ofstream fout("flip.in");
    fout << s;
    fout.close();
    return 0;
}