// 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: 2.567597124196352x):
#include <bits/stdc++.h>

#include <ext/pb_ds/assoc_container.hpp>

#include <ext/pb_ds/tree_policy.hpp> 

#include <ext/pb_ds/detail/standard_policies.hpp>

using namespace __gnu_pbds;

using namespace std;

#define getbit(n, i) (((n) & (1LL << (i))) != 0) 

#define setbit0(n, i) ((n) & (~(1LL << (i)))) 

#define setbit1(n, i) ((n) | (1LL << (i))) 

#define togglebit(n, i) ((n) ^ (1LL << (i))) 

#define lastone(n) ((n) & (-(n))) 

char gap = 32;

template<typename T> 

ostream& operator<<(ostream &os, const vector<T> &v) { 

    os << '{'; 

    for (const auto &x : v) os << gap << x;

        return os << '}'; 

}

template<typename A, typename B> 

ostream& operator<<(ostream &os, const pair<A, B> &p) {

        return os << '(' << p.first << gap << p.second << ')';

}



template <class T>

void read(T &x) {

    char c;

    for (c = getchar(); c < '0' || c > '9'; c = getchar())

        ;

    for (x = 0; c <= '9' && c >= '0'; c = getchar()) x = x * 10 + (c & 15);

}

#define ll long long 

#define lll __int128_t

#define pb push_back

#define mp make_pair

typedef pair < int,int> ii;

typedef vector<ii> vii;

typedef vector<ll>vl;

typedef vector<int> vi;

typedef vector<vi> vvi;

typedef tree<

int,

null_type,

less<int>,

rb_tree_tag,

tree_order_statistics_node_update>

ordered_set;

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

ll hashPrime = 1610612741;

ll n;

ll a[200005];

ll b[200005];

ll c[200005];

ll dp[200005][4];

ll recurse(ll day,ll prev){

    if(day==n){

    	if(prev==1){

    		return max(b[day],c[day]);

		}

		else if(prev==2){

			return max(a[day],c[day]);

		}

		else{

				return max(b[day],a[day]);

			}

		}

		if(dp[day][prev]!=-1)

		  return dp[day][prev];

		//if(prev==0){

			//return max(recurse(day+1,1),max(recurse(day+1,2),recurse(day+1,3)));

	//	}

		if(prev==1){

			return dp[day][prev]=max(b[day]+recurse(day+1,2),c[day]+recurse(day+1,3));

		}

		else if(prev==2){

			return dp[day][prev]=max(a[day]+recurse(day+1,1),c[day]+recurse(day+1,3));

		}

		else if(prev==3){

			return dp[day][prev]=max(b[day]+recurse(day+1,2),a[day]+recurse(day+1,1));

		}

}

int main()

    {

       ios_base::sync_with_stdio(false);

        cin.tie(0);

        ll i,j,k,l,m;

        cin>>n;

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

        	dp[i][1]=-1;

        	dp[i][2]=-1;

        	dp[i][3]=-1;

		}

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

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

		}

		ll maxi=max(recurse(1,1),max(recurse(1,2),recurse(1,3)));

		cout<<maxi;

    	return 0;

}