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

using namespace std;













#define pf                  printf

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

#define sfl(a)              scanf("%lld",&a)

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

#define sffl(a,b)           scanf("%lld %lld",&a,&b)

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

#define sfffl(a,b,c)        scanf("%lld %lld %lld",&a,&b,&c)

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

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

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

#define sfffffl(a,b,c,d,e)  scanf("%lld %lld %lld %lld %lld",&a,&b,&c,&d,&e)

#define sfc(a)              scanf("%c",&a)

#define pii                 pair<int,int>

#define ms(a,b)             memset(a,b,sizeof(a))

#define pb(a)               push_back(a)

#define pbp(a,b)            push_back({a,b})

#define db                  double

#define ft                  float

#define ll                  long long

#define ull                 unsigned long long

#define pii                 pair<int,int>

#define ff                  first

#define ss                  second

#define sz(x)               x.size()

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

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

#define max3(a, b, c)       max(a, b) > max(b, c) ? max(a, b) : max(b, c)

#define min3(a, b, c)       min(a, b) < min(b, c) ? min(a, b) : min(b, c)

#define for0(i,n)           for(int i=0;i<n;i++)

#define for1(i,n)           for(int i=1;i<=n;i++)

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

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

#define forba(i,b,a)        for(int i=b;i>=a;i--)

#define stlloop(x)          for(__typeof(x.begin()) it=x.begin();it!=x.end();it++)

#define gcd(a, b)           __gcd(a, b)

#define lcm(a, b)           ((a)*((b)/gcd(a,b)))

#define case1(z)            cout<<"Case "<<z<<": "

#define case2(z)            printf("Case %d: ",z)

#define PI                  acos(-1) //3.14159265358979323846264338328

#define valid(tx,ty)        tx>=0 && tx<row && ty>=0 && ty<col

#define intlim              2147483648

#define N                   100005

#define inf                 100000008

#define mod                 1000000007



/*------------------------------Graph Moves----------------------------*/

//const int fx[]={+1,-1,+0,+0};

//const int fy[]={+0,+0,+1,-1};

//const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1};   // Kings Move

//const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1};  // Kings Move

//const int fx[]={-2, -2, -1, -1,  1,  1,  2,  2};  // Knights Move

//const int fy[]={-1,  1, -2,  2, -2,  2, -1,  1}; // Knights Move

/*---------------------------------------------------------------------*/















int main()

{

    ll n,i,j,x;

    ll a[N][4],dp[N][4];

    cin>>n;

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

    {

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

        {

            cin>>a[i][j];

        }

    }

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

    {

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

        {

            if(i==0)

            {

                dp[i][j]=a[i][j];

            }

            else

            {

                if(j==0)

                {

                    dp[i][j]=max(dp[i-1][1]+a[i][j],dp[i-1][2]+a[i][j]);

                }

                else if(j==1)

                {

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

                }

                else

                {

                    dp[i][j]=max(dp[i-1][1]+a[i][j],dp[i-1][0]+a[i][j]);

                }

            }

        }

    }

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

    //{

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

    //    {

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

    //    }

    //    cout<<endl;

    //}

    x=max(dp[n-1][0],dp[n-1][1]);

    x=max(x,dp[n-1][2]);

    cout<<x<<endl;

	return 0;

}
































































// Faster C++ solution for the same problem (measured speedup: 5.979158011067908x):
#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;

}