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

#include <algorithm>

#include <iostream>

#include <iomanip>

#include <cstdio>

#include <cstdlib>

#include <cmath>

#include <cstring>

#include <vector>

#include <string>

#include <climits>

#include <map>

#include <set>

#include <stack>

#include <queue>

#include <deque>

#include <stdio.h>

//#define int long long

using namespace std;

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

#define endl '\n'

#define OnlineJudgec

#define F first

#define S second

#define  precision(n)  cout << fixed << setprecision(n)

#define clr(v,d ) memset(v, d, sizeof(v))

typedef long long ll;

typedef vector<int> vi;

void init()

{

    cin.tie(0);

    cin.sync_with_stdio(0);

    cout.tie(0);

    #ifdef OnlineJudge

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

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

    #endif

}

ll S(ll x){ll s = 0;while(x){s += x % 10;x /= 10;}return s;} /// sum of digits.

ll powe(ll a , ll n){if(n == 1)return a;return a * powe(a ,n-1);}

ll com(int n,int m){ll z = 1;for(int i = 0; i < m;i++){z = z * ( n - i) / (i + 1) ;}return z;}

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

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

int dr[] = {0,0,0,1,1,1,-1,-1,-1};

int dc[] ={-1,0,1,-1,0,1,-1,0,1};

/// <<------------------------------------------------------------------------------>>

const int mx = 100009;

int n , k;

int arr[mx][4];

int dp[mx][4];

int solve(int idx , int last)

{

     if(idx == n)return 0;

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

     if(~ret) return ret;

     int A = 0 ,B = 0 ,C = 0;

     if(last != 0)

        A = solve(idx+1 , 0) + arr[idx][0];

     if(last != 1)

        B = solve(idx+1 , 1) + arr[idx][1];

     if(last != 2)

        C = solve(idx+1 , 2) + arr[idx][2];

     return ret = max(A,max(B,C));

}

/// <<------------------------------------------------------------------------------>>

int main()

{

    init();

    cin >> n;

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

    {

        cin >> arr[i][0] >> arr[i][1] >> arr[i][2];

    }

    clr(dp,-1);

    cout<<solve(0,3);

}


// Faster C++ solution for the same problem (measured speedup: 2.5795983428902147x):
/* BISMILLAHIR RAHMANIR RAHIM */

#include<bits/stdc++.h>

using namespace std;

#define ll        long long

#define ull       unsigned long long

#define sd(x)     scanf("%lf", &x)

#define l0(i,n)   for(ll i=0; i<n; i++)

#define MAX       100005

#define maxn 	  200005

#define pb 		  push_back

#define mk 		  make_pair

#define endl	  "\n"

#define INF 	  1000000000

#define MOD		  1000000007

#define imie(...) "[" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "





int main()

{

	int n;

	cin >> n;

	vector<int> hap[n+5];

	vector<int> dp[n+5];

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

	{

		int a,b,c;

		cin >> a >> b >> c;

		hap[i].pb(a);

		hap[i].pb(b);

		hap[i].pb(c);

		dp[i].pb(0);

		dp[i].pb(0);

		dp[i].pb(0);

	}

	//memset(dp,0,sizeof(dp));

	dp[0][0] = hap[0][0];

	dp[0][1] = hap[0][1];

	dp[0][2] = hap[0][2];

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

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

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

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

	}

	int ans = *max_element(dp[n-1].begin(),dp[n-1].end());

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

//	{

//		ans = max(ans,dp[n-1][i]);

//	}

	cout << ans << endl;

	return 0;

}