// 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: 1.1298964892265344x):
#include <bits/stdc++.h>

#include <ext/pb_ds/assoc_container.hpp>

#include <ext/pb_ds/tree_policy.hpp> 

#include <ext/pb_ds/detail/standard_policies.hpp>

using namespace __gnu_pbds;

using namespace std;

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

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

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

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

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

char gap = 32;

template<typename T> 

ostream& operator<<(ostream &os, const vector<T> &v) { 

    os << '{'; 

    for (const auto &x : v) os << gap << x;

        return os << '}'; 

}

template<typename A, typename B> 

ostream& operator<<(ostream &os, const pair<A, B> &p) {

        return os << '(' << p.first << gap << p.second << ')';

}



template <class T>

void read(T &x) {

    char c;

    for (c = getchar(); c < '0' || c > '9'; c = getchar())

        ;

    for (x = 0; c <= '9' && c >= '0'; c = getchar()) x = x * 10 + (c & 15);

}

#define ll long long 

#define lll __int128_t

#define pb push_back

#define mp make_pair

typedef pair < int,int> ii;

typedef vector<ii> vii;

typedef vector<ll>vl;

typedef vector<int> vi;

typedef vector<vi> vvi;

typedef tree<

int,

null_type,

less<int>,

rb_tree_tag,

tree_order_statistics_node_update>

ordered_set;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

ll hashPrime = 1610612741;

ll n;

ll a[200005];

ll b[200005];

ll c[200005];

ll dp[200005][4];

ll recurse(ll day,ll prev){

    if(day==n){

    	if(prev==1){

    		return max(b[day],c[day]);

		}

		else if(prev==2){

			return max(a[day],c[day]);

		}

		else{

				return max(b[day],a[day]);

			}

		}

		if(dp[day][prev]!=-1)

		  return dp[day][prev];

		//if(prev==0){

			//return max(recurse(day+1,1),max(recurse(day+1,2),recurse(day+1,3)));

	//	}

		if(prev==1){

			return dp[day][prev]=max(b[day]+recurse(day+1,2),c[day]+recurse(day+1,3));

		}

		else if(prev==2){

			return dp[day][prev]=max(a[day]+recurse(day+1,1),c[day]+recurse(day+1,3));

		}

		else if(prev==3){

			return dp[day][prev]=max(b[day]+recurse(day+1,2),a[day]+recurse(day+1,1));

		}

}

int main()

    {

       ios_base::sync_with_stdio(false);

        cin.tie(0);

        ll i,j,k,l,m;

        cin>>n;

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

        	dp[i][1]=-1;

        	dp[i][2]=-1;

        	dp[i][3]=-1;

		}

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

        	cin>>a[i]>>b[i]>>c[i];

		}

		ll maxi=max(recurse(1,1),max(recurse(1,2),recurse(1,3)));

		cout<<maxi;

    	return 0;

}