#include <iostream>
using namespace std;
int answer = 0;
int h, w;
void find_a_way(int *array[], int count, int pos_x, int pos_y){
    count = count + array[pos_x][pos_y];
    if((pos_x!=h) || (pos_y!=w)) {
        if(pos_x!=::h){
            find_a_way(array, count, pos_x+1, pos_y);
        };
        if(pos_y!=w){
            find_a_way(array, count, pos_x, pos_y+1);
        };
    }
    else{
        if(count>::answer){
            ::answer = count;
        };
    };
}

int main ()
{

    freopen("/Users/maksimgolish/Desktop/text.txt", "r", stdin);
    freopen("/Users/maksimgolish/Desktop/answer.txt", "w", stdout);
    cin>>::h>>::w;
    int** field;
    field = new int*[h];
    for(int i=0; i<w; i++){
        field[i]=new int[w];
    };
    for(int i=0; i<h, i++;){
        for(int j=0; j<w; j++){
            cin>>field[w][h];
        }
    };

    find_a_way(field, 0, 0, h);
    cout<<::answer;

    return 0;
}