#include <iostream>
#include <algorithm>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
using namespace std;

int cache[101][101] = {0};
int data[101][101]  = {0};

int main()
{
    int n, m;

	cin >> n >> m;

	for (int i=0; i<n; i++) {
		for (int j=0; j<m; j++) {
			cin >> data[i][j];
			cache[i][j] = -99999;
		}
	}

	for (int i=0; i<m; i++) {
		cache[0][i] = data[0][i];
	}


	for (int i=1; i<n; i++) {
		int ret = -99999;
		for (int j=0; j<m; j++) {
			ret = max(ret, cache[i-1][j]);
			for (int k=j+1; k<m; k++) {
				cache[i][k] = ret + data[i][k];
				//ret = max(ret, cache[i-1][j] + data[i][k]);
			}
			//cache[i][j] = ret;
		}
	}

	int ret = -99999;
	for (int i=0; i<m; i++)
		ret = max(ret, cache[n-1][i]);

	cout << ret << endl;

	/*for (int i=0; i<n; i++) {
		for (int j=0; j<m; j++) {
			cout << data[i][j] << " ";
		}
		cout << endl;
	}
	cout << "-------------\n";
	for (int i=0; i<n; i++) {
		for (int j=0; j<m; j++) {
			cout << cache[i][j] << " ";
		}
		cout << endl;
	}*/
}