// Slower C++ solution:
#include <bits/stdc++.h>

using namespace std;



int n;

int dp[100100][4];

vector<int> arr[100100];



int main() {

    cin >> n;

    for (int i = 1; i <= n; ++i) {

        int k;

        for (int j = 0; j < 3; ++j) {

            cin >> k;

            arr[i].push_back(k);

        }

    }



    for (int i = 0; i < 3; ++i) dp[1][i] = arr[1][i];



    for (int pos = 2; pos <= n; ++pos) {

        for (int j = 0; j < 3; ++j) {



            if ( j == 0 ) 

                dp[pos][j] = arr[pos][j] + max(dp[pos - 1][1], dp[pos - 1][2]);

            

            else if ( j == 1 )

                dp[pos][j] = arr[pos][j] + max(dp[pos - 1][0], dp[pos - 1][2]);



            else

                dp[pos][j] = arr[pos][j] + max(dp[pos - 1][0], dp[pos - 1][1]);

        }

    }



    cout << max({dp[n][0], dp[n][1], dp[n][2]}) << endl;

    return 0;

}


// Faster C++ solution for the same problem (measured speedup: 3.494465700070103x):
//#pragma GCC target("avx2")

//#pragma GCC optimize("O3")

   

//#include <x86intrin.h>

#include <bits/stdc++.h>   

#include <ext/pb_ds/assoc_container.hpp>

#include <ext/pb_ds/tree_policy.hpp>

 

using namespace __gnu_pbds;

using namespace std;



template<typename T> using ordered_set = tree <T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

     

#define F first

#define S second           

#define lb lower_bound               

#define ub upper_bound

#define pb push_back

#define pf push_front    

#define ppb pop_back

#define mp make_pair                                     

#define bpp __builtin_popcountll                                                                                        

#define sqr(x) ((x) * (x)) 

#define al 0x3F3F3F3F

#define sz(x) (int)x.size()

#define all(x) x.begin(), x.end()

#define in insert

#define ppf pop_front

#define endl '\n'

//#define int long long

 

typedef unsigned long long ull;

typedef long long ll;

typedef long double ld;

typedef pair <int, int> pii;

 

const int mod = (int)1e9 + 7;

const int N = (int)3e5 + 123;

const ll inf = (ll)1e18 + 1;



const double pi = acos (-1.0);

const double eps = 1e-7;                  

const int dx[] = {0, 0, 1, 0, -1};

const int dy[] = {0, 1, 0, -1, 0};



int n, a[N][4], dp[N][4];



inline void boost () {                    

   ios_base :: sync_with_stdio (NULL);

   cin.tie (NULL), cout.tie (NULL);          

}                                                     



inline void Solve () {

   cin >> n;

   for (int i = 1; i <= n; i ++) cin >> a[i][1] >> a[i][2] >> a[i][3];

   for (int i = 1; i <= n; i ++) {

      dp[i][1] = max (dp[i - 1][2], dp[i - 1][3]) + a[i][1];

      dp[i][2] = max (dp[i - 1][1], dp[i - 1][3]) + a[i][2];

      dp[i][3] = max (dp[i - 1][1], dp[i - 1][2]) + a[i][3];

   }                                              

   cout << max (max (dp[n][1], dp[n][2]), dp[n][3]);

      

     

}



main () {                                       

// freopen (".in", "r", stdin);    

// freopen (".out", "w", stdout);              

   boost ();

   int tt = 1;

   //cin >> tt;   

   while (tt --) {

      Solve ();

   }                                               

   return 0;      

}