/*BISMILLAH UR RAHMAN*/ 
/* AUTHOR -CARLOSRAMIREZ *///Perfection is achieved only on the point of collapse
#include <bits/stdc++.h>
#define endl "\n"
#define pb push_back
#define all(v) v.begin(),v.end()
#define debug(x) std::cerr << #x << ": " << (x) << '\n';
#define sz(x) int(x.size())
#define INF INT_MAX;
using namespace std;
typedef long long int ll;
vector<tuple<int,int,int>> v(int(1e5+10));
int store[4][int(1e5+10)];
int dp(int n,int pre)
{
  if(n<=0)return 0;
  if(store[pre][n])return store[pre][n];
  int ans=0,a,b,c;
  tie(a,b,c)=v[n];
  if(pre==1)
    ans=max(b+dp(n-1,2),c+dp(n-1,3));
  else if(pre==2)
    ans=max(a+dp(n-1,1),c+dp(n-1,3));
  else
    ans=max(a+dp(n-1,1),b+dp(n-1,2));
   return store[pre][n]=ans;
}
int main()
{ 
  int n;cin>>n;
  for(int i=1,x,y,z;i<=n;++i)
  {
    cin>>x>>y>>z;v[i]=make_tuple(x,y,z);
  }
  int ans=INT_MIN;
  int a,b,c;
  tie(a,b,c)=v[n];
  vector<int> v1{a,b,c};
  for(int i=1;i<=3;++i)
  ans=max(ans,v1[i-1]+dp(n-1,i));
  cout<<ans<<endl;
}