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

#define ull unsigned long long

#define ll long long

#define pb push_back

#define endl '\n'

#define line cout<<"----------------------"<<endl

#define mp make_pair

#define mod 1000000007

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

#define filein freopen("input.txt","r",stdin)

#define fileout freopen("output.txt","w",stdout)

using namespace std;

const ll  mx=300009;

struct edge

{

    ll  a,b,c;

};

vector<edge> v;

ll  dp[100009][4];

ll  call(ll  ind, ll  pre)

{

    if(ind==v.size()) return 0;

    ll  &ret=dp[ind][pre];

    if(ret!=-1) return ret;

    ret=0;

    ll  a=0,b=0,c=0;

    auto x=v[ind];

        if(pre==1)

        {

            a=x.b+call(ind+1,2);

            b=x.c+call(ind+1,3);

        }

        else if(pre==2)

        {

            a=x.a+call(ind+1,1);

            b=x.c+call(ind+1,3);

        }

        else if(pre==3)

        {

            a=x.a+call(ind+1,1);

            b=x.b+call(ind+1,2);

        }

        else

        {

            a=x.a+call(ind+1,1);

            b=x.b+call(ind+1,2);

            c=x.c+call(ind+1,3);

        }

    return ret=max(a,max(b,c));

}

int  main()

{

    ll  n ;

    cin>>n;

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

    {

        ll  a,b,c; cin>>a>>b>>c;

        v.pb({a,b,c});

    }

    memset(dp,-1,sizeof dp);

    cout<<call(0,0)<<endl;







}


// Faster C++ solution for the same problem (measured speedup: 1.2360552895768848x):
#include<bits/stdc++.h>

#define lld         long long int

#define llf         long double

#define pb          push_back

#define mp          make_pair

#define IN          insert

#define loopN(n)    for(lld i=0;i<n;i++)

#define loop(p,n)   for(lld i=p;i<=n;i++)

#define rloop(p,n)  for(lld i=n;i>=p;i--)

#define loop2(p,n)  for(lld j=p;j<=n;j++)

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

#define F1          first

#define F2          second

#define INF         2e18

#define FILE        freopen("input.txt","r",stdin);freopen("output.txt","w",stdout)

#define PI          2*acos(0.0)

#define ISO         ios::sync_with_stdio(false);cin.tie(0)

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

#define case(z)     cout<<"Case "<<z<<": ";

using namespace std;

const lld mod=1e9+7;



lld on(lld m,lld p){return m | (1<<p);}

bool ison(lld m,lld p){return (bool)(m & (1<<p));}

lld flip(lld m,lld p){return m ^ (1<<p);}

lld allon(lld p){return (1<<p)-1;}

//______________________________________________________________________________________



lld n;

lld dp[100005][3];

lld a[100005][3];



lld fun(lld p, lld k)

{

    if(p>=n)return 0;

    if(dp[p][k]!=-1)

    {

        return dp[p][k];

    }

    lld ans=-INF;

    if(p==0)

    {

        loopN(3)

        {

            ans=max(ans,a[p][i]+fun(p+1,i));

        }

        return ans;

    }

    else

    {

        loopN(3)

        {

            if(i!=k)

            {

                ans=max(ans,a[p][i]+fun(p+1,i));

            }



        }



    }

    return dp[p][k]=ans;







}





int main()

{

    ISO;



    //lld t;cin>>t;while(t--)

    mem(dp,-1);

    cin>>n;

    loopN(n)loop2(0,2)cin>>a[i][j];

    cout<<fun(0,0)<<endl;





    return 0;

}