//Campo de Minhocas - 2293 - URI
//Henrique B. L.

#include <iostream>

using namespace std;

int main()
{
    int L, C;

    cin >> L >> C;

    int worms[L][C], highest = 0;

    for(int i = 0; i < L; i++)
        for(int j = 0; j < C; j++)
            cin >> worms[i][j];


    for(int i = 0; i < L; i++)
    {
        int s = 0;

        for(int j = 0; j < C; j++)
        {
            int S = 0;

            for(int k = 0; k < L; k++)
            {
                S+= worms[k][j];

                if(S > highest)
                    highest = S;
            }

            s+= worms[i][j];

            if(s > highest)
                highest = s;
        }
    }

    cout << highest << endl;
}