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

using namespace std;

#define print printf("==================\n")

#define ll long long

#define pi acos(-1.0)

#define eps 1e-16

#define max3(a,b,c) max(a,max(b,c))

const ll INF = 1 << 30;

typedef pair<ll, ll  > payar;

typedef struct

{

    ll  x, y;

} point;

priority_queue<payar, vector<payar>,  greater<payar> > pq; ///accending

vector< pair<ll,payar  > > vpp;

vector < payar >  vp;



ll n ;

int ara[100005][4];

ll dp[100005][4];

ll cal(int day, int itm)

{

    if(day>n)

    {

        return 0;

    }



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

        return dp[day][itm];

    ll maxi = -1;

    if(day==1)

    {

   return   maxi = dp[day][itm]=max3( cal(day+1,1)+ara[day][1], cal(day+1,2)+ara[day][2], cal(day+1,3)+ara[day][3] );



    }

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

    {

            if(i==itm)

                continue;

            maxi=max( cal(day+1,i)+ara[day][i],maxi);





    }

    return dp[day][itm]=maxi;

}



int main()

{



    cin>>n;

    memset(dp,-1,sizeof dp);

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

    {

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

        {

            cin>>ara[i][j];

        }

    }

    cout<<cal(1,1);







    return  0 ;

}


// Faster C++ solution for the same problem (measured speedup: 4.171424113873895x):
//#pragma GCC target ("avx2,sse2")

//#pragma GCC optimization ("Ofast")

//#pragma GCC optimization ("unroll-loops")

#include <bits/stdc++.h>

#include <ext/pb_ds/assoc_container.hpp>

#include <ext/pb_ds/tree_policy.hpp>

using namespace __gnu_pbds;



#define ordered_set tree <pair <ll, int>, null_type, less <pair <ll, int> >, rb_tree_tag, tree_order_statistics_node_update>

#define ll long long

#define ull unsigned long long

#define db long double

#define pb push_back

#define pf push_front

#define ppb pop_back

#define ppf pop_front

#define fi first

#define se second

#define mp make_pair

#define up_b upper_bound

#define low_b lower_bound

#define sz(x) (int)(x).size()

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

#define endl "\n"



#define left fsdsdfoisf

#define sum dpsdfioppsf

#define assign xcvjlkdjfio

#define trie fksdfkjkfnjuiv

#define next sidlfjsfkl

#define merge sdfksdkfsldf



#define int long long



using namespace std;



void dout() {

    cerr << endl;

}

template <typename Head, typename... Tail>

void dout(Head H, Tail... T) {

    cerr << H << ' ';

    dout(T...);

}



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

typedef pair <int, int> pii;



const int N = 1e5 + 7;

int n, c[3][N], dp[3][N];



void solve(int tc) {

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

    cin >> n;

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

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

            cin >> c[j][i];

        }

    }

    for (int i = 0; i < 3; i++) {

        dp[i][1] = c[i][1];

    }

    for (int i = 2; i <= n; i++) {

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

            dp[j][i] = max({dp[j][i], dp[(j + 1) % 3][i - 1], dp[(j + 2) % 3][i - 1]}) + c[j][i];

        }

    }

    int res = 0;

    for (int i = 0; i < 3; i++) {

        res = max(res, dp[i][n]);

    }

    cout << res;

}



signed main() {

    ios_base::sync_with_stdio(false);

    cin.tie(NULL);

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

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

    int tc = 1;

//    cin >> tc;

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

        solve(i);

//        cleanup();

    }

}