// 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: 1.138125196640559x):
#include <bits/stdc++.h>



#define cn count

#define pb push_back

#define in insert

#define fs first

#define sc second

#define sz size

#define len length

#define forn(i, n) for (ll i = 0; i < (ll) (n); ++i)

#define forni(i, n) for (ll i = 1; i < (ll) (n); ++i)

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



using namespace std;

using ll = long long;

const ll inf = 1e9+7; 

const double PI =  3.141592653589793;



int main(){

	IO;

	ll n,abc[3],ans = 0;

	cin>>n;

	ll dp[n+1][3];

	memset(dp,0,sizeof(dp));

	forni(i,n+1){

		forn(j,3) cin>>abc[j];

		forn(j,3){

			forn(k,3) if(k!=j)dp[i][j] = max(dp[i][j],dp[i-1][k] + abc[j]);

		}

	}

	forn(i,3) ans = max(dp[n][i],ans);

	cout<<ans<<'\n';

	return 0;

}





// _   .-')                .-. .-')                 .-')                                               

//( '.( OO )_              \  ( OO )               ( OO ).                                             

// ,--.   ,--.).-'),-----. ,--. ,--.  .-'),-----. (_)---\_) ,--. ,--.     .-----.  ,-.-')  .-'),-----. 

// |   `.'   |( OO'  .-.  '|  .'   / ( OO'  .-.  '/    _ |  |  | |  |    '  .--./  |  |OO)( OO'  .-.  '

// |         |/   |  | |  ||      /, /   |  | |  |\  :` `.  |  | | .-')  |  |('-.  |  |  \/   |  | |  |

// |  |'.'|  |\_) |  |\|  ||     ' _)\_) |  |\|  | '..`''.) |  |_|( OO )/_) |OO  ) |  |(_/\_) |  |\|  |

// |  |   |  |  \ |  | |  ||  .   \    \ |  | |  |.-._)   \ |  | | `-' /||  |`-'| ,|  |_.'  \ |  | |  |

// |  |   |  |   `'  '-'  '|  |\   \    `'  '-'  '\       /('  '-'(_.-'(_'  '--'\(_|  |      `'  '-'  '

// """    """     """""""" """  """"      """""""  """""""  """"""""      """"""   """         """""""