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

using namespace std;

typedef long long ll;



ll arr[100009][3];

int dp[100009][2][2][2];



long long VAC1(int n,int a, int b, int c)

{



    if(!n && a) return arr[n][0];

    else if(!n && b) return arr[n][1];

    else if(!n && c) return arr[n][2];

    else if(dp[n][a][b][c]!=-1)return dp[n][a][b][c];



    else

    {



        ll x,y,z;

        if(a)

        {

            x = VAC1(n-1,0,1,0)+arr[n][0];

            y = VAC1(n-1,0,0,1)+arr[n][0];



        }



        else if(b)

        {

            x = VAC1(n-1,1,0,0)+arr[n][1];

            y = VAC1(n-1,0,0,1)+arr[n][1];

        }



        else if(c)

        {

            x = VAC1(n-1,1,0,0)+arr[n][2];

            y = VAC1(n-1,0,1,0)+arr[n][2];

        }



        dp[n][a][b][c] = max(x,y);;

        return dp[n][a][b][c];





    }

}



int main()

{

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

    int n;

    memset(dp,-1,sizeof(dp));

    cin >> n;

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

    {

        for(int j=0; j<3; j++)

        {

            cin >> arr[i][j];

        }

    }

    ll res = VAC1(n-1,1,0,0);

    res= max(res, VAC1(n-1,0,1,0));

    res = max(res,VAC1(n-1,0,0,1));



    cout << res << endl;

}


// Faster C++ solution for the same problem (measured speedup: 4.097506431542027x):
//                                 Alisher_2211

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        # include <bits/stdc++.h>

# define  long          long long

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

# define  allr(vc)      vc.rbegin(),vc.rend()

# define  pb            push_back

# define  fi            first 

# define  se            second

# define  pi            pair <long, long>    

# define  lcm(a, b)     (a * b) / __gcd(a, b)

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        using namespace std;

const long N = 100100;

void read(){freopen("input.txt" , "r" , stdin );freopen("output.txt", "w" , stdout );}

long dp[N][3];

long n, k;

void solve(){

    cin >> n;

    long ar[n + 5][5];

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

    {

        for (int j = 0; j < 3; ++j)

        {

            cin >> ar[i][j];

        }

    }

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

    {

        for (int j = 0; j < 3; ++j)

        {

            if( !j ) 

                dp[i][0] = max( dp[i - 1][1], dp[i - 1][2] ) + ar[i][0];

            if( j == 1 ) 

                dp[i][1] = max( dp[i - 1][0], dp[i - 1][2] ) + ar[i][1];

            else 

                dp[i][2] = max( dp[i - 1][1], dp[i - 1][0] ) + ar[i][2];// <=

        }

    }

    cout << max({ dp[n][0], dp[n][1], dp[n][2] });

}

int32_t main(){

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

        long T = 1;

        //cin >> T;

        while( T-- ){

            solve();

            cout<<'\n';

        }

cerr << "\nTime elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << " s.\n";

}