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

using namespace std;



#define MAX_N 100005

int N, h[MAX_N][3], memo[MAX_N][3];



int main() {

  scanf("%i", &N);

  for (int d = 0; d < N; d++) {

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

  	  scanf("%i", &h[d][c]);

	}

  }

  memset(memo, -1, sizeof memo);

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

  	memo[0][c] = h[0][c];

  }

  for (int d = 1; d < N; d++) {

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

  	  int &opt = memo[d][c];

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

  	    if (cc != c) {

  	      opt = max(opt, memo[d - 1][cc] + h[d][c]);

		  /*

  	      if (d == 1) {

  	        printf("%i %i %i %i\n", memo[d - 1][cc], h[d][c], cc, c);

		  }

		  */

		}

	  }

	}

  }

  /*

  puts("\ndebug");

  for (int d = 0; d < N; d++) {

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

  	  printf("%i ", memo[d][c]);

	}

	puts("");

  }

  puts("end-debug\n");

  */

  int ans = -1;

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

  	ans = max(ans, memo[N - 1][c]);

  }

  printf("%i\n", ans);

  

}

// Faster C++ solution for the same problem (measured speedup: 2.162377482839507x):
//#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;      

}