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

using namespace std;

#define ll long long

ll a[100009],b[100009],c[100009];

int dp[100009][3];

int main() {

    ios::sync_with_stdio(false);

    int n;cin>>n;

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

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

    memset(dp,0x3f, sizeof(dp));

    dp[1][0]=a[1];dp[1][1]=b[1];dp[1][2]=c[1];

    for(int i=2;i<=n;i++){

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

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

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

    }

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

    return 0;

}


// Faster C++ solution for the same problem (measured speedup: 2.155832191876761x):
//                                 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";

}