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

using namespace std;

typedef long long ll;

typedef unsigned long long ull;

const int N = 1e5+10 , OO = 0x3f3f3f3f ;

//const int mod = 1000000007;

 

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

double startTime;

double getCurrentTime() {

	return ((double)clock() - startTime) / CLOCKS_PER_SEC;

}

#define clr(arr,val) memset(arr , val , sizeof (arr))

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

#define rloop(i,n) for(int i = int(n)-1;i >= 0;i--)

#define xloop(i,a,b) for(int i = int(a);i <= int(b);i++)

#define range(vec) for(auto &x : vec) cin >> x;

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

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

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

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

//int dx[]={2,1,-1,-2,-2,-1,1,2};int dy[]={1,2,2,1,-1,-2,-2,-1};//Knight Direction

//int dx[6]={2,1,-1,-2,-1,1};int dy[6]={0,1,1,0,-1,-1}; //Hexagonal Direction

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

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



int a[N] , b[N] , c[N] , n;

int dp[N][4];



int solve(int idx , int lst){

	

	if(idx == n) return 0;

	int& ret = dp[idx][lst];

	if(~ret) return ret;

	ret = -OO;

	if(lst != 0) // swim

		ret = max(ret , solve(idx+1 , 0) + a[idx]);

	if(lst != 1)

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

	if(lst != 2)

		ret = max(ret , solve(idx+1 , 2) + c[idx]);

		

	return ret;

}





int main()

{

    startTime = (double)clock();

    #ifndef ONLINE_JUDGE

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

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

    #endif

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

	

	cin >> n;

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

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



	clr(dp , -1);

	cout << solve(0 , 3) << "\n";





    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 2.5647267962926814x):
#define _CRT_SECURE_NO_WARNINGS

#include<bits/stdc++.h>

#include<unordered_map>

using namespace std;

//<DEFINE>

void Fast() {

	ios::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);

}

void File() {

#ifndef ONLINE_JUDGE

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

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

#endif

}

#define ll long long

#define ull unsigned long long

#define mod 1000000007

ll gcd(ll a, ll b) {

	return!b ? a : gcd(b, a % b);

}

#define fix(n) cout << fixed << setprecision(n);

#define numOfOnes(n) __builtin_popcount(n)

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

#define skip continue

#define stop(n) return cout<<n,0

#define pi  acos(-1)

#define endl "\n"

#define ceil(x,y) (x+y-1)/y

//</DEFINE>



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int n,k;

vector<vector<int>>v;

int res[100002][4];

int solve(int idx = 0,int current =0) {

	if (idx == n+1)return 0;

	if (~res[idx][current])return res[idx][current];

	int mx = 0;

	for (int i = 1; i <= 3; i++) {

		if (i == current)skip;

		mx = max(v[idx][i] + solve(idx + 1, i),mx);

	}

	return res[idx][current] = mx;

}

//</FUNCTIONS>		

int main() {

	Fast();

	cin >> n;

	v = vector<vector<int>>(n+1, vector<int>(4));

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

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

			res[i][j] = -1;

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

		for (int j = 1; j <= 3; j++)

			cin >> v[i][j];

	}

	cout << solve() << endl;

}