#include<bits/stdc++.h>
using namespace std;
 
int n;
int arr[20][3];
 
///a=0    b=1    c=2
 
int rec(int i,int last)
{
  if(i==n) return 0;
  int result=0;
 
  if(last!=0)result=max(result , arr[i][0] + rec(i+1,0) );
  if(last!=1)result=max(result , arr[i][1] + rec(i+1,1) );
  if(last!=2)result=max(result , arr[i][2] + rec(i+1,2) );
 
  return result;
}
 
 
int main()
{
  cin >> n;
  for(int i=0;i<n;++i){cin >> arr[i][0] >> arr[i][1] >> arr[i][2];}
  cout << rec(0,-1);
}
 

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7
6 7 8
8 8 3
2 5 2
7 8 6
4 6 8
2 3 4
7 5 1