// Slower C++ solution:
#include <iostream>

#include <cstring>

#include <stdio.h>

using namespace std;

const int N=1e+5;

int n,a[N],b[N],c[N];

int memo[N][4];

int dp(int i,int t)

{

    if(i==n)

        return 0;

    int &ret=memo[i][t];

    if(~ret)

        return ret;

    ret=0;

    if(t!=0)

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

    if(t!=1)

        ret=max(ret,dp(i+1,1)+b[i]);

    if(t!=2)

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

    return ret;





}

int main()

{

    memset(memo,-1,sizeof memo);

    scanf("%d",&n);

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

    {

         scanf("%d %d %d",a+i,b+i,c+i);

    }

    printf("%d\n",dp(0,3));

    return 0;

}


// Faster C++ solution for the same problem (measured speedup: 2.5183875578262414x):
//                                 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";

}