// 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: 1.1249758246587356x):
#include <bits/stdc++.h>

#define ll          long long int

#define pii         pair<int,int>

#define uu          first

#define vv          second

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

using namespace std;



const int MAX = 1e6 + 6;

int main()

{

    fastIO;

    int n;

    cin>>n;

    vector< vector<int> >vec(n+1, vector<int>(4)), dp(n+1, vector<int>(4));

    

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

        cin>>vec[i][1]>>vec[i][2]>>vec[i][3];

    }

    

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

        

        for(int k = 1 ; k <=3 ; k++ ) {

            

            for(int kk = 1 ; kk <=3 ; kk++ ) {

                

                if(kk == k ) continue;

                

                dp[i][k] = max(dp[i][k], dp[i-1][kk] + vec[i][k]);

            }

        }

    }

    

    cout<<max(dp[n][1], max(dp[n][2], dp[n][3]))<<'\n';

    return 0;

}