#include<iostream>
#include<cstdio>
using namespace std;
int Bag[54][2],p=0;//dp
void cpy(){
	for(int i=1;i<=30;i++)
		Bag[i][p]=Bag[i][p^1];
}
int main(){
	freopen("teacher.in","r",stdin);
	freopen("teacher.out","w",stdout);
	int m,n,v;cin>>m>>n;
	while(m--){
		for(int j=1;j<=n;j++){
			cin>>v;// Use j Get v
			for(int k=0;k<=n;k++)if((!k||Bag[k][p])&&k+j<=n)Bag[k+j][p^1]=max(Bag[k+j][p^1],Bag[k][p]+v);
		}
		cpy();
	}
	cout<<Bag[n][p];
	fclose(stdin);
	fclose(stdout);
	return 0;
}