// Slower C++ solution:
#define _CRT_SECURE_NO_WARNINGS

#include<bits/stdc++.h>

#include<unordered_map>

#include<unordered_set>	

using namespace std;

typedef long long ll;

#define bay_bay return 0;

#define fori(n) for(int i=0;i<n;++i)

#define for1(n) for(int i=1;i<=n;i+=3)

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

#define sz(v) v.size()

#define endl "\n"

constexpr auto EPS = 1e-9;

#define ff fflush(stdout);

const int mod = 1000000007LL;

clock_t T;

#define ctime cerr << "Time : " << double(clock() - T) / CLOCKS_PER_SEC << endl

void GOAT()

{

	std::ios_base::sync_with_stdio(0);

	cin.tie(NULL);

	cout.tie(NULL);

#ifndef ONLINE_JUDGE

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

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

#else

#endif

}

struct day

{

	ll a, b, c;



};

day days[100009];

ll mem[100009][4];

int n;

ll solve(int idx, int ch)

{

	if (idx == n)

	{

		return 0;

	}

	ll &ret = mem[idx][ch];

	if (~ret)

		return ret;

	ret = LLONG_MIN;

	if (ch != 1)

		ret=max(ret, days[idx].a + solve(idx + 1, 1));

	if (ch != 2)

		ret=max(ret, days[idx].b + solve(idx + 1, 2));

	if (ch != 3)

		ret=max(ret, days[idx].c + solve(idx + 1, 3));

	return ret;



}

int main()

{

	//GOAT();

	cin >> n;

	memset(mem, -1,sizeof mem);

	fori(n)

	{

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

	}

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

	

}

// Faster C++ solution for the same problem (measured speedup: 4.098976928748849x):
//                                 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";

}