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

using namespace std;

typedef long long ll;

typedef unsigned long long ull;

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

#define     bug(a,b)        cout<<a<<"\t"<<b<<"\n";

#define     Case(a,b)       cout<<"Case "<<a<<": "<<b<<"\n";

#define     watch(a)        cout<<fixed<<setprecision(a)

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

#define     Endl            "\n";

#define     tab             "\t"

#define     reset(a,b)      memset(a,b,sizeof(a));

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

#define     srt(a)          sort(a.begin(),a.end());

#define     pi              2*acos(0.0)

#define     inf             INT_MAX

const int sz=1e5+9;

int n,x,arr[sz][3],dp[sz][3];



int clac(int i,int ignore ,int value){

    if(i>n)return value;

    if(dp[i][ignore]!=-1)return dp[i][ignore];

    int ret=0;

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

        if(j==ignore)

            continue;

        ret=max(ret,value+clac(i+1,j,arr[i][j]));

    }

    return dp[i][ignore]=ret;

}



void solve(){

    cin>>n;

    reset(dp,-1);

    //cout<<dp[2][0]<<tab<<dp[2][1]<<tab<<dp[2][2]<<endl;

    lp(i,1,n+1)cin>>arr[i][0]>>arr[i][1]>>arr[i][2];

    int ans1=clac(2,0,arr[1][0]);

    //cout<<dp[2][0]<<tab<<dp[2][1]<<tab<<dp[2][2]<<endl;

    int ans2=clac(2,1,arr[1][1]);

    int ans3=clac(2,2,arr[1][2]);

    //cout<<ans1<<tab<<ans2<<tab<<ans3<<endl;

    //int ans=max(ans1,(max(ans2,ans3)));

   // bug(ans1,1);

    cout<<max(ans1,(max(ans2,ans3)))<<"\n";

}



int main(){

    //FasterIO;

    #ifndef ONLINE_JUDGE

       //freopen("1.txt","r",stdin);

    #endif

    // int t;

    //cin>>t;

    //while(t--)

        solve();

}


// Faster C++ solution for the same problem (measured speedup: 2.203399464210579x):
#include <bits/stdc++.h>

using namespace std;

#define INF 2000000000

typedef long long int ll;

typedef pair<ll,ll> ii;

typedef vector<ll> vi;

typedef vector<ii> vii;

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

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

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

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

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

#define read freopen("debug\\in.txt","r",stdin)

#define write freopen("debug\\out.txt","w",stdout)

#define fi first

#define se second

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

#define getII(a,b) scanf("d",&a,&b)

#define PI (acos(-1))

#define fastread ios_base::sync_with_stdio(false);cin.tie(NULL)

#define mod (1000000007)

#define asz 500005

#define t int t;scanf("%d",&t);for(int v=1;v<=t;v++)

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

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

#define minheap priority_queue<int,vector<int>,greater<int> >

#define maaheap priority_queue<int>

#define pb push_back

#define newl "\n"

ll BIGMOD ( ll a, ll p, ll m )

{

    ll result = 1;

    ll x = a;



    while ( p )

    {

        if ( p & 1 ) //p is odd

        {

            result = ( result * x ) % m;

        }

        x = ( x * x ) % m;

        p = p >> 1;

    }



    return result;

}



bool isPrime(int n)

{

    if (n <= 1)  return false;

    if (n <= 3)  return true;

    if (n%2 == 0 || n%3 == 0) return false;



    for (int i=5; i*i<=n; i=i+6)

        if (n%i == 0 || n%(i+2) == 0)

           return false;



    return true;

}



void SieveOfEratosthenes(int n)

{

    bool prime[n+1];

    memset(prime, true, sizeof(prime));



    for (int p=2; p*p<=n; p++)

    {



        if (prime[p] == true)

        {

            for (int i=p*p; i<=n; i += p)

                prime[i] = false;

        }

    }

}

const int MAX=100005;

ll memo[MAX][3];

 int arr[MAX][3];

 int n;

 void init()

 {

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

     {

         for(int j=0;j<3;j++) memo[i][j]=-1;

     }

 }

ll vacation(int i,char current)

{

    if(i==n) return 0;

    if(memo[i][current-'A']!=-1) return memo[i][current-'A'];

    if(current=='A')

    {

        ll res1=arr[i][0]+vacation(i+1,'B');

        ll res2=arr[i][0]+vacation(i+1,'C');

        return memo[i][0]=max(res1,res2);

    }

    if(current=='B')

    {

        ll res1=arr[i][1]+vacation(i+1,'A');

        ll res2=arr[i][1]+vacation(i+1,'C');

        return memo[i][1]=max(res1,res2);

    }

    if(current=='C')

    {

        ll res1=arr[i][2]+vacation(i+1,'A');

        ll res2=arr[i][2]+vacation(i+1,'B');

        return memo[i][2]=max(res1,res2);

    }





}



int main()

{

  // fastread;

   cin>>n;

   init();

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

   {

       for(int j=0;j<3;j++) cin>>arr[i][j];

   }

   ll res1=vacation(0,'A');

   ll res2=vacation(0,'B');

   ll res3=vacation(0,'C');

   cout<<max(res1,max(res2,res3))<<newl;

  return 0;

}