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

#include <queue>

#include <string>

#include <map>

#include <stdio.h>

#include <iomanip>

#include <math.h>

#include <vector>

#include <stack>

#include <algorithm>

#include <string.h>

#include <set>

#include <cstdlib>

#include <iostream>

#include <bits/stdc++.h>

#define pii pair<int,int> 

#define ll long long int 

#define sl(n) scanf("%lld",&n)

#define s(n) scanf("%d",&n)

#define f(i,n) for(int i=0;i<n;++i)

#define fo(i,n) for(int i=1;i<=n;++i)

#define fnm(n,m) for(ll i=n;i<m+1;++i)

#define pb push_back

#define pf printf

#define F first

#define S second

#define srt(v) sort(v.begin(),v.end());

#define srtc(v,cmp) sort(v.begin(),v.end(),cmp);

#define srta(v,n) sort(v,v+n);

const ll LL_INF=0x3f3f3f3f3f3f;

const ll MOD=1073741824;





using namespace std;





int T;

int d,arr[100005][5];

int dp[100005][5];



int gen(int i,int prev){ // swim:0, bugs:1, homework:2

    if(i == d)return 0;

    int &ret = dp[i][prev];

    if(~ret)return ret;

    ret = gen(i+1,(prev+1)%3)+arr[i][(prev+1)%3];

    ret = max( ret , gen(i+1,(prev+2)%3)+arr[i][(prev+2)%3]);

    if(!i)ret = max( ret , gen(i+1,(prev)%3)+arr[i][(prev)%3]);

    return ret;

}



int main(){

    // pf("\t\t\t***************************************************************************\n\n");

    // pf("\t\t\t***************************************************************************\n\n");

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

    // freopen("output.txt","w",stdout);

    memset(dp,-1,sizeof dp);

    s(d);

    f(i,d){

        s(arr[i][0]);

        s(arr[i][1]);

        s(arr[i][2]);

    }

    pf("%d\n",gen(0,0));



    return 0;

} 

// Faster C++ solution for the same problem (measured speedup: 2.9508611101016915x):
//I solved it before. If I had enough time I wouldn't have submitted old codes.

//If you forbid I won't do this in the upcoming contests

#include <iostream>

#include <vector>

#include <cmath>

#include <set>

#include <queue>

#include <map>

#include <cstdio>

#include <cstring>

#include <string>

#include <stack>

#include <algorithm>

#include <limits.h>

#include <bits/stdc++.h>

#define fw(x) freopen("x.txt","w",stdout)

#define For(i,a,b,c) for(int i = a;i < b;i+=c)

#define REP(i,n) for(int i = 0;i < n;++i)

#define REP1(i,n) for(int i = 1; i<=n;i++)

#define mem(a,s) memset(a,s,sizeof a)

#define fast ios_base::sync_with_stdio(0);cin.tie(NULL)

#define pf printf

#define sc scanf

#define ll long long

#define pii pair<int,int>

#define pll pair<ll,ll>

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

#define vii vector<int>

#define vll vector<ll>

#define vss vector<string>

#define debug(x)  cout<<#x"="<<(x)<<endl

#define pb push_back





using namespace std;





// moves



//int dx[]= {0,0,1,-1};/*4 side move*/

//int dy[]= {-1,1,0,0};/*4 side move*/

//int dx[]= {1,1,0,-1,-1,-1,0,1};/*8 side move*/

//int dy[]= {0,1,1,1,0,-1,-1,-1};/*8 side move*/

//int dx[]={1,1,2,2,-1,-1,-2,-2};/*knight move*/

//int dy[]={2,-2,1,-1,2,-2,1,-1};/*knight move*/





//big_mod



//ll bigmod(ll a,ll b,ll m)

//{if(b == 0) return 1%m;ll x = bigmod(a,b/2,m);x = (x * x) % m;if(b % 2 == 1) x = (x * a)% m;return x;}

//ll BigMod(ll B,ll P,ll M){ ll R=1%M; while(P>0) {if(P%2==1){R=(R*B)%M;}P/=2;B=(B*B)%M;} return R;} /// (B^P)%M



//ll getBit(ll num, int idx) {return ((num >> idx) & 1ll) == 1ll;}

//ll setBit1(ll num, int idx) {return num or (1ll<<idx);}

//ll setBit0(ll num, int idx) {return num & ~(1ll<<idx);}

//ll flipBit(ll num, int idx) {return num ^ (1ll<<idx);}



const int mod = 1000000007;

ll qpow(ll n,ll k)

{

    ll ans=1;

    assert(k>=0);

    n%=mod;

    while(k>0)

    {

        if(k&1)

            ans=(ans*n)%mod;

        n=(n*n)%mod;

        k>>=1;

    }

    return ans%mod;

}

int ar[100009][3];

int sum[100009][3];

void run(int i, int pre, int n){

    if(i>=n) return;

    int sum1=0, sum2=0, sum3=0;

    if(pre!=0){

        if(sum[i+1][0] == -1 ) run(i+1, 0, n);

        sum1 = ar[i][pre] + sum[i+1][0];

    }

    if(pre!=1){

        if(sum[i+1][1] == -1 ) run(i+1, 1, n);

        sum2 = ar[i][pre] + sum[i+1][1];

    }

    if(pre!=2){

        if(sum[i+1][2] == -1 ) run(i+1, 2, n);

        sum3 = ar[i][pre] + sum[i+1][2];

    }

    sum[i][pre] = max(sum1, max(sum2, sum3));

}

int main()

{

    fast;

    int n, a, b, c;

    cin>>n;

    REP1(i, n){

        cin>>a>>b>>c;

        sum[i][0]= -1;

        sum[i][1]= -1;

        sum[i][2]= -1;

        ar[i][0] = a;

        ar[i][1] = b;

        ar[i][2] = c;

    }

    sum[n][0] = ar[n][0];

    sum[n][1] = ar[n][1];

    sum[n][2] = ar[n][2];

    run(1, 0, n);

    run(1, 1, n);

    run(1, 2, n);

    cout<< max(sum[1][0], max(sum[1][1], sum[1][2]) ) <<'\n';

    return 0;

}