#include <iostream>
#include <fstream>

int main()
{
    std::ifstream fin("flip.in");
    unsigned int N, M;
    fin >> N >> M;

    int table[N][M];
    for(unsigned int i = 0; i < N; i++)
        for(unsigned int j = 0; j < M; j++)
            fin >> table[i][j];
    fin.close();

    int sum = 0;

    for(unsigned int i = 0; i < N; i++)
        for(unsigned int j = 0; j < M; j++)
            sum += table[i][j];

    int maximum = sum;

    for(unsigned int i = 0; i < N; i++)
    {
        for(unsigned int j = 0; j < M; j++)
        {
            unsigned int x = i, y = j;
            sum = 0;
            for(unsigned int r = 0; r < N; r++)
            {
                for(unsigned int c = 0; c < M; c++)
                {
                    if(x == r || y == c)
                        sum += -table[r][c];
                    else
                        sum += table[r][c];
                }
            }
            if(sum > maximum)
                maximum = sum;
        }
    }

    std::ofstream fout("flip.out");
    fout << maximum;
    fout.close();

    return 0;
}