// Slower C++ solution:
#define __USE_MINGW_ANSI_STDIO

#define _CRT_SECURE_NO_WARNINGS

#include <bits/stdc++.h>

#include <unordered_set>

#include <unordered_map>



using namespace std;



typedef long long ll;

typedef long long ull;

typedef pair<ll, ll> ii;



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

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

#define endl		"\n"

#define fx(n)		fixed<<setprecision(n)

#define mk			make_pair	



void File()

{

#ifndef ONLINE_JUDGE

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

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

#endif

#ifdef ONLINE_JUDGE

	/*freopen("output.txt", "w", stdout);

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

#endif

}

void fast()

{

	ios::sync_with_stdio(NULL);

	cout.tie(NULL);

	cin.tie(NULL);

	//File();

}

const double pi = 2 * acos(0.0);

const ll oo = 0x3f3f3f3f;

const int MOD = 1e9 + 7;

const int nn = 1e5 + 15;

int dx[8] = { 1, -1, 0, 0, 1, -1, 1, -1 };

int dy[8] = { 0, 0, 1, -1, 1, -1, -1, 1 };



int n, k;

vector<pair<int, pair<int, int>>>v;

ll dp[nn][4];

ll solve(int idx, int last)

{

	if (idx >= n)

		return 0;

	ll &ret = dp[idx][last];

	if (~ret)

		return ret;

	ret = 0;

	if (last != 1)

		ret = max(ret, solve(idx + 1, 1) + v[idx].first);



	if (last != 2)

		ret = max(ret, solve(idx + 1, 2) + v[idx].second.first);



	if (last != 3)

		ret = max(ret, solve(idx + 1, 3) + v[idx].second.second);



	return ret;

}

int main()

{

	fast();

	cin >> n;

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

	{

		int x, y, z;

		cin >> x >> y >> z;

		v.push_back(mk(x, mk(y, z)));

	}

	memset(dp, -1, sizeof(dp));

	cout << solve(0, 0) << endl;

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 4.119190702710557x):
//                                 Alisher_2211

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        # include <bits/stdc++.h>

# define  long          long long

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

# define  allr(vc)      vc.rbegin(),vc.rend()

# define  pb            push_back

# define  fi            first 

# define  se            second

# define  pi            pair <long, long>    

# define  lcm(a, b)     (a * b) / __gcd(a, b)

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        using namespace std;

const long N = 100100;

void read(){freopen("input.txt" , "r" , stdin );freopen("output.txt", "w" , stdout );}

long dp[N][3];

long n, k;

void solve(){

    cin >> n;

    long ar[n + 5][5];

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

    {

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

        {

            cin >> ar[i][j];

        }

    }

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

    {

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

        {

            if( !j ) 

                dp[i][0] = max( dp[i - 1][1], dp[i - 1][2] ) + ar[i][0];

            if( j == 1 ) 

                dp[i][1] = max( dp[i - 1][0], dp[i - 1][2] ) + ar[i][1];

            else 

                dp[i][2] = max( dp[i - 1][1], dp[i - 1][0] ) + ar[i][2];// <=

        }

    }

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

}

int32_t main(){

ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); 

        long T = 1;

        //cin >> T;

        while( T-- ){

            solve();

            cout<<'\n';

        }

cerr << "\nTime elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << " s.\n";

}