//                                 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";
}

Measured memory_bytes: 9936