// Slower C++ solution:
/**       In the name of Allah, the Gracious, the Merciful.

*               Praise be to Allah, Lord of the Worlds.

*               **************************************

*

*    I have not failed, I have just found 1000 WAYS that won't work.

*                 __________________________________

*                  Author  : Abd El-Twab  M. Fakhry

*                 __________________________________

*/



#include <ext/rope>

#include <bits/stdc++.h>

#include <ext/pb_ds/tree_policy.hpp>

#include <ext/pb_ds/assoc_container.hpp>



#define  print(arr, l, r)    for(int i = (l); i < (r); cout << arr[i++] << " \n"[i == r])

#define  read(arr, l, r)     for(int i = (l); i < (r); cin >> arr[i++])

#define  repr(i, r, l)       for (int i = r; i > l; i--)

#define  rep(i, l, r)        for (int i = l; i < r; i++)

#define  Unique(n)           (n).erase(unique(all(n)), (n).end())

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

#define  RT(n)               return cout << (n) << endl, 0;

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

#define  endl                '\n'

#define  D(x)                cout << #x << " = " << (x) << '\n'

#define  F                   first

#define  S                   second

#define  PB                  push_back

#define  EB                  emplace_back

#define  lsb(x)              (x & -x)

#define  get(n)              find_by_order(n)

#define  sqrt(n)             sqrtl(n)

#define  pow(a, b)           powl(a, b)

#define  indexOf(n)          order_of_key(n)

#define  isPowerOfTwo(x)     (x && !(x & (x - 1)))



using namespace std;

using namespace __gnu_pbds;

using namespace __gnu_cxx;



typedef long long            ll;

typedef unsigned long long   ull;



/**---------------------->>  Constants  <<-----------------------**/



const double    Pi      = 2 * acos(0.0),    Euler = 2.71828182845904523536,

                Epsln   = 1e-9,           GoldenR = (1 + sqrtl(5.0)) / 2;



const ll        MgcPrim = 2305843009213693951;

const int       MxsZ    = (int)1e5 + 9,        oo = 0x3f3f3f3f,

 		        ModB2   = (1 << 30) + 7,   ModBT7 = (int)1e9 + 7, ModBT = (int)1e9;



/**---------------->>  Functions & Shortcuts  <<-----------------**/



template <class T>

T Gcd(T a, T b) { return b ? Gcd(b, a % b) : a; }



template <class T>

T Lcm(T a, T b) { return a / Gcd(a, b) * 1ll * b; }



template <class T> /** Phi(a * b) = Phi(a) * Phi(b) where a and b Prime Factors and k their power **/

T Phi(T a, T k) { return pow(a, k - 1) * (a - 1); }



template <class T>

using indexed_set = tree <T, null_type, less <T>, rb_tree_tag, tree_order_statistics_node_update >;



template <class T>

using matrix = vector < vector <T> >;



template <class T>

using min_heap = priority_queue < T, vector <T>, greater <T> >;



/** Watch **/



template <class T>

string ToString(T x) { stringstream sout; sout << x; return sout.str(); }



#ifdef BFS

int dx8[8] = { 1, -1, 0, 0, 1, 1, -1, -1 }, dx4[4] = { 0, 0, 1,-1};

int dy8[8] = { 0, 0, 1, -1, 1, -1, 1, -1 }, dy4[4] = { 1,-1, 0, 0};

#endif // BFS



/**------------------>>  Fast input / output  <<-----------------**/



void Fast()

{

    cin.sync_with_stdio(0);

    cin.tie(0);cout.tie(0);

    cin.exceptions(cin.failbit);

}



/**----------------->>  input / output Files  <<-----------------**/



void File()

{

    #ifdef FIO

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

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

   	#endif // FIO

}



/**------------------>>  Initialization gap  <<------------------**/



int n, a[MxsZ][4], dp[MxsZ][4], mx = -oo;



int Vac(int nx, int type)

{

    if(nx < 0) return 0;

    int &ret = dp[nx][type];

    if(~ret) return ret;



    if(type == 1) return ret = a[nx][type] + max(Vac(nx - 1, 2), Vac(nx - 1, 3));

    if(type == 2) return ret = a[nx][type] + max(Vac(nx - 1, 1), Vac(nx - 1, 3));

    if(type == 3) return ret = a[nx][type] + max(Vac(nx - 1, 2), Vac(nx - 1, 1));

}



inline void Solve()

{

    cin >> n;

    rep(i, 0, n) cin >> a[i][1] >> a[i][2] >> a[i][3];



    rep(i, 1, 4)

    {

        memset(dp, -1, sizeof dp);

        mx = max(mx, Vac(n - 1, i));

    }

    cout << mx << endl;

}



/**------------------------->>  Main  <<-------------------------**/



int main()

{

    Fast(); File(); Solve();

}


// Faster C++ solution for the same problem (measured speedup: 3.5540631874222575x):
// #pragma GCC optimize("Ofast,O3,unroll-loops")

// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma")



#include <vector>

#include <list>

#include <map>

#include <set>

#include <deque>

#include <queue>

#include <stack>

#include <bitset>

#include <algorithm>

#include <functional>

#include <numeric>

#include <utility>

#include <iostream>

#include <sstream>

#include <iomanip>

#include <cstdio>

#include <cmath>

#include <cstdlib>

#include <cctype>

#include <string>

#include <cstring>

#include <cstdio>

#include <cmath>

#include <cstdlib>

#include <ctime>

#include <climits>

#include <complex>

#include <ext/pb_ds/assoc_container.hpp>

#include <ext/pb_ds/tree_policy.hpp>



using namespace __gnu_pbds;

using namespace std;



#define endl '\n'

#define hoise cerr<<"hoise - "<<__LINE__<<"\n"

#define tham getchar()

#define set0(ar) memset(ar, 0, sizeof ar)

#define setinf(ar) memset(ar, 126, sizeof ar)

#define vsort(v) sort(v.begin(), v.end())

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

#define FASTIO ios::sync_with_stdio(false);cin.tie(nullptr)



using ll = long long;

using pii = pair <int, int>;

using pll = pair <ll, ll>;

using vi = vector <int>;

using vl = vector <ll>;

using vpii = vector < pii >;

using vpll = vector < pll >;



const int LOG = 20;

const int N = (int)2e5+6;

const double PI = acos(-1.0);

const ll MOD = 1e9 + 7;

const int INF = 1e9;

const double EPS = 1e-6;

const int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};

const int knight_x[8] = {2, 1, -1, -2, -2, -1, 2, 1}, knight_y[8] = {1, 2, 2, 1, -1, -2, -1, -2};



#define dbg(args...) { string _s = #args; replace(_s.begin(), _s.end(), ',', ' '); stringstream _ss(_s); istream_iterator<string> _it(_ss); err(_it, args); }

void err(istream_iterator<string> it) {}

template<typename T, typename... Args>

void err(istream_iterator<string> it, T a, Args... args) {

    cerr << *it << " = " << a << " ";

    err(++it, args...);

    cout << endl;

}



int flipBit (int mask, int k) { return mask = mask ^ (1 << k); }

bool checkBit (int mask, int k) { return (mask >> k) & 1; }

int setBit (int mask, int k) { return mask = mask | (1 << k); }

int resetBit (int mask, int k) { if (checkBit (mask, k)) { mask = flipBit (mask, k); } return mask; }



inline void normal(ll &a) { a %= MOD; (a < 0) && (a += MOD); }

inline ll modMul(ll a, ll b) { a %= MOD, b %= MOD; normal(a), normal(b); return (a * b) % MOD; }

inline ll modAdd(ll a, ll b) { a %= MOD, b %= MOD; normal(a), normal(b); return (a + b) % MOD; }

inline ll modSub(ll a, ll b) { a %= MOD, b %= MOD; normal(a), normal(b); a -= b; normal(a); return a; }

inline ll modPow(ll b, ll p) { ll r = 1; while (p) { if (p & 1) r = modMul(r, b); b = modMul(b, b); p >>= 1; } return r; }

inline ll modInverse(ll a) { return modPow(a, MOD - 2); }

inline ll modDiv(ll a, ll b) { return modMul(a, modInverse(b)); }



template <typename T> using orderedSet = tree<T, null_type, greater<T>, rb_tree_tag, tree_order_statistics_node_update>;

template <typename T> using orderedSet1 = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;



bool equalTo ( double a, double b ) { if ( fabs ( a - b ) <= EPS ) return true;	else return false; }

bool notEqual ( double a, double b ){ if ( fabs ( a - b ) > EPS ) return true;	else return false; }

bool lessThan ( double a, double b ){ if ( a + EPS < b ) return true;	else return false; }

bool lessThanEqual ( double a, double b ){ if ( a < b + EPS ) return true;	else return false;}

bool greaterThan ( double a, double b ){ if ( a > b + EPS ) return true;	else return false;}

bool greaterThanEqual ( double a, double b ){ if ( a + EPS > b ) return true;	else return false;}



int kase;



/*--------------------------------------------------------------------------------------------------------------------------*/



void solution () {

	int n;

	cin >> n;

	vi a (n), b (n), c (n);

	vector <vector <int> > dp (n + 1, vector <int> (3, 0));

	

	for (int i = 0; i < n; ++i) {

		cin >> a[i] >> b[i] >> c[i];

	}

	

	for (int i = n - 1; i >= 0; --i) {

		dp[i][0] = max (b[i] + dp[i + 1][1], c[i] + dp[i + 1][2]);

		dp[i][1] = max (a[i] + dp[i + 1][0], c[i] + dp[i + 1][2]);

		dp[i][2] = max (a[i] + dp[i + 1][0], b[i] + dp[i + 1][1]);

	}

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

}



int main() {

	FASTIO;

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

	int tc;

	// cin >> tc;

	tc = 1;

	

	while (tc--) {

		solution ();

	}

	

    return 0;

}



/*

 * check corner cases

 * be careful before submitting in Lightoj, SPOJ, UVA

*/