// 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: 4.257897506995382x):
#include <bits/stdc++.h>



using namespace std;



int choose(const int &day, const int &last_activity, const int activities[][3], const int &n, int memo[][4]){

    int ans;

    if(day == n){

        ans = 0;

    }

    else{

        if(memo[day][last_activity] != -1){

            ans = memo[day][last_activity];

        }

        else if(last_activity == 0){

            ans = memo[day][0] = max(activities[day][0] + choose(day + 1, 1, activities, n, memo), max(activities[day][1] + choose(day + 1, 2, activities, n, memo), activities[day][2] + choose(day + 1, 3, activities, n, memo)));

        }

        else if(last_activity == 1){

            ans = memo[day][1] = max(activities[day][1] + choose(day + 1, 2, activities, n, memo), activities[day][2] + choose(day + 1, 3, activities, n, memo));

        }

        else if(last_activity == 2){

            ans = memo[day][2] = max(activities[day][0] + choose(day + 1, 1, activities, n, memo), activities[day][2] + choose(day + 1, 3, activities, n, memo));

        }

        else{

            ans = memo[day][3] = max(activities[day][0] + choose(day + 1, 1, activities, n, memo), activities[day][1] + choose(day + 1, 2, activities, n, memo));

        }

    }

    return ans;

}



int solve(const int activities[][3], const int &n, int memo[][4]){

    return choose(0, 0, activities, n, memo);

}



int main(){

    int n;

    while(scanf("%d", &n) != EOF){

        int activities[n][3], memo[n][4];

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

            scanf("%d %d %d", &activities[i][0], &activities[i][1], &activities[i][2]);

            memo[i][0] = -1; memo[i][1] = -1; memo[i][2] = -1; memo[i][3] = -1;

        }

        printf("%d\n", solve(activities, n, memo));

    }

    return 0;

}