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

using namespace std;

typedef long long ll;

typedef unsigned long long ull;

#define     FasterIO        ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);

#define     bug(a,b)        cout<<a<<"\t"<<b<<"\n";

#define     Case(a,b)       cout<<"Case "<<a<<": "<<b<<"\n";

#define     watch(a)        cout<<fixed<<setprecision(a)

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

#define     Endl            "\n";

#define     tab             "\t"

#define     reset(a,b)      memset(a,b,sizeof(a));

#define     sf(a)           scanf(" %d", &a);

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

#define     pi              2*acos(0.0)

#define     inf             INT_MAX

const int sz=1e5+9;

int n,x,arr[sz][3],dp[sz][3];



int clac(int i,int ignore ,int value){

    if(i>n)return value;

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

    int ret=0;

    for(int j=0;j<3;j++){

        if(j==ignore)

            continue;

        ret=max(ret,value+clac(i+1,j,arr[i][j]));

    }

    return dp[i][ignore]=ret;

}



void solve(){

    cin>>n;

    reset(dp,-1);

    //cout<<dp[2][0]<<tab<<dp[2][1]<<tab<<dp[2][2]<<endl;

    lp(i,1,n+1)cin>>arr[i][0]>>arr[i][1]>>arr[i][2];

    int ans1=clac(2,0,arr[1][0]);

    //cout<<dp[2][0]<<tab<<dp[2][1]<<tab<<dp[2][2]<<endl;

    int ans2=clac(2,1,arr[1][1]);

    int ans3=clac(2,2,arr[1][2]);

    //cout<<ans1<<tab<<ans2<<tab<<ans3<<endl;

    //int ans=max(ans1,(max(ans2,ans3)));

   // bug(ans1,1);

    cout<<max(ans1,(max(ans2,ans3)))<<"\n";

}



int main(){

    //FasterIO;

    #ifndef ONLINE_JUDGE

       //freopen("1.txt","r",stdin);

    #endif

    // int t;

    //cin>>t;

    //while(t--)

        solve();

}


// Faster C++ solution for the same problem (measured speedup: 2.1648371735420446x):
#include <bits/stdc++.h>

#include <ext/pb_ds/assoc_container.hpp>

#include <ext/pb_ds/tree_policy.hpp> 

#include <ext/pb_ds/detail/standard_policies.hpp>

using namespace __gnu_pbds;

using namespace std;

#define getbit(n, i) (((n) & (1LL << (i))) != 0) 

#define setbit0(n, i) ((n) & (~(1LL << (i)))) 

#define setbit1(n, i) ((n) | (1LL << (i))) 

#define togglebit(n, i) ((n) ^ (1LL << (i))) 

#define lastone(n) ((n) & (-(n))) 

char gap = 32;

template<typename T> 

ostream& operator<<(ostream &os, const vector<T> &v) { 

    os << '{'; 

    for (const auto &x : v) os << gap << x;

        return os << '}'; 

}

template<typename A, typename B> 

ostream& operator<<(ostream &os, const pair<A, B> &p) {

        return os << '(' << p.first << gap << p.second << ')';

}



template <class T>

void read(T &x) {

    char c;

    for (c = getchar(); c < '0' || c > '9'; c = getchar())

        ;

    for (x = 0; c <= '9' && c >= '0'; c = getchar()) x = x * 10 + (c & 15);

}

#define ll long long 

#define lll __int128_t

#define pb push_back

#define mp make_pair

typedef pair < int,int> ii;

typedef vector<ii> vii;

typedef vector<ll>vl;

typedef vector<int> vi;

typedef vector<vi> vvi;

typedef tree<

int,

null_type,

less<int>,

rb_tree_tag,

tree_order_statistics_node_update>

ordered_set;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

ll hashPrime = 1610612741;

ll n;

ll a[200005];

ll b[200005];

ll c[200005];

ll dp[200005][4];

ll recurse(ll day,ll prev){

    if(day==n){

    	if(prev==1){

    		return max(b[day],c[day]);

		}

		else if(prev==2){

			return max(a[day],c[day]);

		}

		else{

				return max(b[day],a[day]);

			}

		}

		if(dp[day][prev]!=-1)

		  return dp[day][prev];

		//if(prev==0){

			//return max(recurse(day+1,1),max(recurse(day+1,2),recurse(day+1,3)));

	//	}

		if(prev==1){

			return dp[day][prev]=max(b[day]+recurse(day+1,2),c[day]+recurse(day+1,3));

		}

		else if(prev==2){

			return dp[day][prev]=max(a[day]+recurse(day+1,1),c[day]+recurse(day+1,3));

		}

		else if(prev==3){

			return dp[day][prev]=max(b[day]+recurse(day+1,2),a[day]+recurse(day+1,1));

		}

}

int main()

    {

       ios_base::sync_with_stdio(false);

        cin.tie(0);

        ll i,j,k,l,m;

        cin>>n;

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

        	dp[i][1]=-1;

        	dp[i][2]=-1;

        	dp[i][3]=-1;

		}

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

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

		}

		ll maxi=max(recurse(1,1),max(recurse(1,2),recurse(1,3)));

		cout<<maxi;

    	return 0;

}