// Don't be dead serious about your life --  it's just like a program
// Never open a ranklist untill and unless you are done with solving problems, wastes 3/4 minutes
// Do not treat CP as a placement thing, love it and enjoy it, you will succeed for sure.

#include <bits/stdc++.h>
using namespace std;
typedef  long long  int ll;
typedef long double ld;
typedef unsigned long long int ull;
//fundamentals
#define pb push_back
#define pf push_front
#define lb(v,val)  (lower_bound(v.begin(),v.end(),val)-v.begin())
#define ub(v,val)  (upper_bound(v.begin(),v.end(),val)-v.begin())
#define line cout<<"\n";
#define sortv(v) sort(v.begin(),v.end())
#define sortvd(v) sort(v.begin(),v.end(),greater<ll>())
#define lcm(a,b) (a*b/gcd(a,b))
#define all(v) ((v).begin(),(v).end())
#define v_at_in(n) *p.find_by_order(ll n)
#define mp make_pair
//loops
#define f(i,a,b) for(ll i=(ll)a;i<(ll)b;i++)
#define rf(i,a,b) for(ll i=(ll)a;i>=(ll)b;i--)
#define f0 for(ll i=0;i<n;i++)
#define f1 for(ll i=1;i<=n;i++)
#define fr for(ll i=n-1;i>=0;i--)
//input of array
#define inarray ll a[n];for(ll i=0;i<n;i++)cin>>a[i];
// starter pack
#define test ll T;cin>>T;while(T--)
#define fast ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
//maximum and minimum
#define max3(a,b,c) max(a,max(b,c))
#define min3(a,b,c) min(a,min(b,c))
#define max4(a,b,c,d) max(a,max3(b,c,d))
#define min4(a,b,c,d) min(a,min3(b,c,d))
#define endl "\n"
//some values
#define PI 3.14159265
const ll MOD=1000000000+7;
const ll MOD1 = 998244353;
const ll Val9=1000000000;
const ll Val6=1000000;
vector<ll>vd;
void no_of_divisors(ll n){
 for (ll i = 1; i <= sqrt(n); i++) {
  if (n % i == 0){
   if(n/i==i)
    {vd.pb(i);
    }
   else
   {vd.pb(i);vd.pb(n/i);
   }
  }
 }
 // no_of_divisors==vd.size();
}

ll pwr(ll x, ll y){
 ll r=1;
 while(y>0){
  if(y&1)
   r=r*x;
  x*=x;
  y>>=1;
 }
 return r;
}

ll pwrm(ll x, ll y, ll m){
 x%=m;
 ll r=1;
 while(y>0){
  if(y&1)
   r=r*x%m;
  x=x*x%m;
  y>>=1;
 }
 return r;
}
int isPrime(ll n)
{
    // Corner cases
    if (n <= 1)
        return 0;
    if (n <= 3)
        return 1;

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

    for (int i = 5; i * i <= n; i = i + 6)
        if (n % i == 0 || n % (i + 2) == 0)
            return 0;

    return 1;
}
ll gcd(ll a, ll b)
{
    if (b == 0)
        return a;
    return gcd(b, a%b);
}
vector<ll>vprime;
vector<ll>vsqr;
void SieveOfEratosthenes(ll n)
{
    bool prime[n+1];
    memset(prime, true, sizeof(prime));

    for (ll p=2; p*p<=n; p++)
    {
        if (prime[p] == true)
        {
            for (ll i=p*p; i<=n; i += p)
                prime[i] = false;
        }
    }
    for (ll p=2; p<=n; p++)
    {  if (prime[p])
       {vprime.pb(p);vsqr.pb(p*p);}
    }
}
 bool vis[Val6]={false};
vector<ll>v[Val6];   // Define dfs
vector<ll>ans;
void dfs(ll s,ll k)
{

    ll p=v[s].size();
    vis[s]=true;             // Change node to true
    f(i,0,v[s].size())      // Loop iterating till depth of that particular node
    {
        if(vis[v[s][i]]==false&&v[s][i]!=k)
        {
            dfs(v[s][i],k);  // Recursive implementation or like backtraping to vist all the nodes in depth
        }                   // & there neighbour nodes at depth
    }
}

void bfs(vector<ll>v[],ll n)
{
    queue<ll>q;
   // ll level[Val6]={0};
    q.push(n);
   // level[n]=1;
    vis[n]=true;
    ll dist=0;
    while(!q.empty())
    {
        ll p=q.front();
        q.pop();
        dist++;
        f(i,0,v[p].size())
        {
            if(vis[v[p][i]]==false){
            //level[ v[ p ][ i ] ] = level[ p ]+1;
           // d[v[p][i]]=dist;
            q.push(v[ p ][ i ]);
            vis[ v[ p ][ i ] ] = true;}
        }
    }
}

ll nCr(ll n, ll r)
{
    ll ans=1;
    f(i,0,r)
    {
        ans*=n-i;
        ans/=i+1;
    }
    return ans;
}
ll dp[Val6][3];
ll n;
ll m,n1,o;
ll a[Val6],b[Val6],c[Val6];

int main()
{

fast;
// Shuru karte hai bina kisi backchodi ke_____
{
        cin>>n;
        f(i,0,n)
        cin>>a[i]>>b[i]>>c[i];
        ll s=0;
        ll a1,b1,c1;
        a1=0;b1=0;c1=0;
        memset(dp,-1,sizeof(dp));
        dp[0][0]=a[0];
        dp[0][1]=b[0];
        dp[0][2]=c[0];
        f(i,1,n)
        {
            dp[i][0]=a[i]+max(dp[i-1][1],dp[i-1][2]);
            dp[i][1]=b[i]+max(dp[i-1][0],dp[i-1][2]);
            dp[i][2]=c[i]+max(dp[i-1][0],dp[i-1][1]);
        }
        cout<<max3(dp[n-1][0],dp[n-1][1],dp[n-1][2]);
}
// End of program Logic

    cerr<<"Time : "<<1000*((double)clock())/(double)CLOCKS_PER_SEC<<"ms\n";
    return 0;
}


Measured memory_bytes: 52960