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

using namespace std;



int const N=1e5+5, M=1e9+7, OO = 0x3f3f3f3f;



int n;

int arr[3][N];



int mem[N][4];

int solve(int i, int last)

{

    if(i==n)

        return 0;

    if(mem[i][last]!=-1)

        return mem[i][last];

    int op1= (last!=1) ? solve(i+1, 1)+arr[0][i] : 0;

    int op2= (last!=2) ? solve(i+1, 2)+arr[1][i] : 0;

    int op3= (last!=3) ? solve(i+1, 3)+arr[2][i] : 0;

    return mem[i][last]=max(op1,max(op2,op3));

}





int main()

{

//    freopen("input.txt","rt",stdin);

//    freopen("output.txt","wt",stdout);

    scanf("%d",&n);

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

        scanf("%d %d %d",arr[0]+i,arr[1]+i,arr[2]+i);

    memset(mem, -1, sizeof mem);

    printf("%d\n",solve(0,0));







    return 0;

}


// Faster C++ solution for the same problem (measured speedup: 2.5567813460090134x):
#include <ext/pb_ds/assoc_container.hpp>

#include <ext/pb_ds/tree_policy.hpp>

#include <functional>

#include<bits/stdc++.h>

using namespace std;

using namespace __gnu_pbds;





typedef tree<int, null_type, less_equal<int>, rb_tree_tag,

             tree_order_statistics_node_update>

    ordered_set;





#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)1073. Square Country

#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                   200005

#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

/*---------------------------------------------------------------------*/









ll dp[N][4],a[N][4];









int main()

{

    ios_base :: sync_with_stdio(0); cin.tie(0); cout.tie(0);

    //freopen("input.txt","r",stdin);

    //freopen("output.txt","w",stdout);

    ll n,i,j;

    cin>>n;

    for1(i,n)

    {

        for1(j,3)

            cin>>a[i][j];

    }



    for1(i,n)

    {

        for1(j,3)

        {

            if(i==1)

                dp[i][j]=a[i][j];

            else

            {

                if(j==1)

                    dp[i][j]=a[i][j]+max(dp[i-1][j+1],dp[i-1][j+2]);

                else if(j==2)

                    dp[i][j]=a[i][j]+max(dp[i-1][j-1],dp[i-1][j+1]);

                else

                    dp[i][j]=a[i][j]+max(dp[i-1][j-1],dp[i-1][j-2]);

            }

        }

    }

    i=max3(dp[n][1] , dp[n][2] , dp[n][3]);

    cout<<i<<endl;

	return 0;

}