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



using namespace std;

typedef long long int lli;



lli n, a[100005], b[100005], c[100005];



lli dp[100005][4];



lli solve(lli i, lli last){

    if(i == n) return dp[i][last] = 0;

    if(dp[i][last] != -1) return dp[i][last];

    lli ans1, ans2, ans3;

    ans1 = ans2 = ans3 = LONG_LONG_MIN;

    if(last != 1) ans1 = a[i] + solve(i+1, 1);

    if(last != 2) ans2 = b[i] + solve(i+1, 2);

    if(last != 3) ans3 = c[i] + solve(i+1, 3);



    return dp[i][last] = max(ans1, max(ans2, ans3));

}





int main(){

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

    int T=1, cs=1;

    //scanf("%d", &T);

    while(T--){

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

        scanf("%lld", &n);

        for(lli i=0; i<n; i++){

            scanf("%lld %lld %lld", &a[i], &b[i], &c[i]);

        }

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



    }



    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 4.078805173435496x):
//                                 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";

}