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

#include <string>

#include <cstdlib>

using namespace std;



#define READ                freopen("in.txt", "r", stdin)

#define WRITE               freopen("out.txt", "w", stdout)



#define si(a)               scanf("%d", &a)

#define sii(a,b)            scanf("%d %d", &a, &b)

#define siii(a,b,c)         scanf("%d %d %d", &a, &b, &c)



#define CLR(a)              memset(a, 0, sizeof(a))

#define SET(a)              memset(a, -1, sizeof(a))



#define PI                  acos(-1.0)



#define pb                  push_back

#define mp                  make_pair

#define SORT(v)             sort(v.begin(), v.end())

#define REV(v)              reverse(v.begin(), v.end())

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

#define FOR1(i, n)          for(int i=1; i<=n; i++)

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

#define ROF1(i, n)          for(int i=n; i>=1; i--)

#define LOOP(i, x, y)       for(int i=x; i<=y; i++)

#define fastIO()            ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);





typedef long long              LL;

typedef unsigned long long     ULL;

typedef vector<int>            VI;

typedef pair<int, int>         PII;

typedef pair<string, int>      PSI;

typedef pair<char, int>        PCI;



const int MAX = 100005;

const LL LMAX = 12158598925;

const double eps = 1e-9;

const int INF = 0x3f3f3f3f;



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

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

int kx[] = {1, 1, 2, 2, -1, -1, -2, -2};

int ky[] = {2, -2, 1, -1, 2, -2, 1, -1};



int n, w;

int arr[MAX][3];

LL dp[MAX][3];







int main()

{

//    READ;

//    WRITE;

    si(n);



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

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

            si(arr[i][j]);

    }



    for(int j=0; j<3; j++) dp[1][j] = arr[1][j];



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

//        cout << "FOR: " << i << ":\n";

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

            LL mx = INT_MIN;

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

                if(q == j) continue;



                mx = max(mx, dp[i-1][q]);

            }



            dp[i][j] = arr[i][j] + mx;

//              cout << " max: " << mx << " arr: " << arr[i][j] << " dp: " << dp[i][j] << endl;

        }

//        cout << endl;

    }



//    cout << endl;

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

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

//            cout << dp[i][j] << " ";

//        }

//        cout << endl;

//    }



    LL ans = INT_MIN;

    for(int j=0; j<3; j++) ans = max(ans, dp[n][j]);



    cout << ans << endl;

    return 0;

}


// Faster C++ solution for the same problem (measured speedup: 5.1447035964122145x):
#include<stdio.h>

#include<stdlib.h>



#define get(a, i, j) *((*(a+i))+j)





typedef long long ll;



//long long **mem, **util, N;

ll mem[100001][3], util[100001][3], N;



ll dp(ll d, ll u);



int main()

{

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



    ll i, max, temp_util;



    //util = (ll**) malloc(N * sizeof(ll*));

    //mem = (ll**) malloc(N * sizeof(ll*));



    scanf("%lld", &N);



    for(i = 0; i<N; ++i){

        //*(util+i) = (ll*) malloc(3 * sizeof(ll));

        //*(mem+i) = (ll*) calloc(3, sizeof(ll));



        scanf("%lld%lld%lld", &get(util, i, 0), &get(util, i, 1), &get(util, i, 2));

    }





    //printf("%lld\n", dp(0, 0));

    max = 0;

    temp_util = 0;



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

        //printf("calling dp(const 0, %lld)\n", i);

        temp_util = dp(0, i);

        if (max < temp_util) max = temp_util;

    }



    printf("%lld\n", max);



    return 0;

}





ll dp(ll d, ll u)

{

    //printf("inside dp with d = %lld, u = %lld\n", d, u);

    if (d == N-1) {

        //printf("returning %lld without setting\n\n", get(util, d, u));

        return get(util, d, u);

    }



    if(get(mem, d, u) > 0) {

        //printf("returning %lld without setting\n\n", get(util, d, u));

        return get(mem, d, u);

    }



    ll i, max, temp_util;



    max = 0;

    temp_util = 0;

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

        if(i!=u) temp_util = dp(d+1, i);

        if(temp_util>max) max = temp_util;

    }



    //printf("setting value in mem[%lld][%lld] = %lld (%lld)\n\n", d, u, get(util, d, u)+max, get(util, d, u));

    return get(mem, d, u) = get(util, d, u) + max;

}