#include<bits/stdc++.h>
using namespace std;
int a[105][105];
int main()
{
    
    int m,n;
    cin>>m>>n;
    for(int i =1;i<=m;i++)
    {
        for(int j = 1;j<=n;j++)
        {
            cin >> a[i][j];
        }
    }
    for(int i = 1;i<=m;i++)
    {
        for(int j = 1;j<=n;j++)
        {
            if(a[i-1][j] > a[i][j-1])
            {
                a[i][j]+=a[i-1][j];
            }
            else
            {
                a[i][j]+=a[i][j-1];
            }
        }
    }
    cout<<a[m][n];
}
/**************************************************************
	Problem: 1298
	User: wuyichen
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2116 kb
****************************************************************/