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

using namespace std;













#define pf                  printf

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

#define sfl(a)              scanf("%lld",&a)

#define sff(a,b)            scanf("%d %d",&a,&b)

#define sffl(a,b)           scanf("%lld %lld",&a,&b)

#define sfff(a,b,c)         scanf("%d %d %d",&a,&b,&c)

#define sfffl(a,b,c)        scanf("%lld %lld %lld",&a,&b,&c)

#define sffff(a,b,c,d)      scanf("%d %d %d %d",&a,&b,&c,&d)

#define sffffl(a,b,c,d)     scanf("%lld %lld %lld %lld",&a,&b,&c,&d)

#define sfffff(a,b,c,d,e)   scanf("%d %d %d %d %d",&a,&b,&c,&d,&e)

#define sfffffl(a,b,c,d,e)  scanf("%lld %lld %lld %lld %lld",&a,&b,&c,&d,&e)

#define sfc(a)              scanf("%c",&a)

#define pii                 pair<int,int>

#define ms(a,b)             memset(a,b,sizeof(a))

#define pb(a)               push_back(a)

#define pbp(a,b)            push_back({a,b})

#define db                  double

#define ft                  float

#define ll                  long long

#define ull                 unsigned long long

#define pii                 pair<int,int>

#define ff                  first

#define ss                  second

#define sz(x)               x.size()

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

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

#define max3(a, b, c)       max(a, b) > max(b, c) ? max(a, b) : max(b, c)

#define min3(a, b, c)       min(a, b) < min(b, c) ? min(a, b) : min(b, c)

#define for0(i,n)           for(int i=0;i<n;i++)

#define for1(i,n)           for(int i=1;i<=n;i++)

#define forrev(i,n)         for(int i=n-1; i>=0; i--)

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

#define forba(i,b,a)        for(int i=b;i>=a;i--)

#define stlloop(x)          for(__typeof(x.begin()) it=x.begin();it!=x.end();it++)

#define gcd(a, b)           __gcd(a, b)

#define lcm(a, b)           ((a)*((b)/gcd(a,b)))

#define case1(z)            cout<<"Case "<<z<<": "

#define case2(z)            printf("Case %d: ",z)

#define PI                  acos(-1) //3.14159265358979323846264338328

#define valid(tx,ty)        tx>=0 && tx<row && ty>=0 && ty<col

#define intlim              2147483648

#define N                   100005

#define inf                 100000008

#define mod                 1000000007



/*------------------------------Graph Moves----------------------------*/

//const int fx[]={+1,-1,+0,+0};

//const int fy[]={+0,+0,+1,-1};

//const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1};   // Kings Move

//const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1};  // Kings Move

//const int fx[]={-2, -2, -1, -1,  1,  1,  2,  2};  // Knights Move

//const int fy[]={-1,  1, -2,  2, -2,  2, -1,  1}; // Knights Move

/*---------------------------------------------------------------------*/















int main()

{

    ll n,i,j,x;

    ll a[N][4],dp[N][4];

    cin>>n;

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

    {

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

        {

            cin>>a[i][j];

        }

    }

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

    {

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

        {

            if(i==0)

            {

                dp[i][j]=a[i][j];

            }

            else

            {

                if(j==0)

                {

                    dp[i][j]=max(dp[i-1][1]+a[i][j],dp[i-1][2]+a[i][j]);

                }

                else if(j==1)

                {

                    dp[i][j]=max(dp[i-1][0]+a[i][j],dp[i-1][2]+a[i][j]);

                }

                else

                {

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

                }

            }

        }

    }

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

    //{

    //    for(j=0;j<3;j++)

    //    {

    //        cout<<dp[i][j]<<" ";

    //    }

    //    cout<<endl;

    //}

    x=max(dp[n-1][0],dp[n-1][1]);

    x=max(x,dp[n-1][2]);

    cout<<x<<endl;

	return 0;

}
































































// Faster C++ solution for the same problem (measured speedup: 1.1410510993102712x):
#include <iostream>

#include <string>

#include<iomanip>

#include <algorithm>

#include <map>

#include <vector>

#include<queue>

#include<math.h>

#include<cmath>

#include<sstream>

#include<set>

#include <map>

#include<string.h>

#include<sstream>

#include<stack>

#include<unordered_map>

#include <iostream>

#include <stdio.h>

#include <stdlib.h>

#include <ctype.h>

#include <cstdio>

#include <cstdlib>

#include <complex>

#define ll long long

#define  point complex<double>

#define  pi acos(-1)

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

#define arr2dof vector  vector<vector<int>>dp(N,vector<int>(2, inf));

using namespace std;

const ll N = 2e5 + 5, mod = 1e9 + 7, inff = -1e12,inf=1e12;

const double ep = 0.0000000001;

//const double pi = 3.14159265359;



double dot(point a, point b) {

	return  (conj(a)*b).real();

}

double cross(point a, point b) {

	return  (conj(a)*b).imag();

}

double angle(point a, point b)

{

	double dt = dot(a, b);

	dt /= abs(a);

	dt /= abs(b);

	return acos(dt) * 180.0 / pi;

}



bool isrightangel(int ind) {//90 degree

	vector<point>v;

	return(angle(v[ind] - v[(ind + 1) % 3], v[ind] - v[(ind + 2) % 3]) == 90);//bshof hal eldot producty3ny fe

	//dl3en 3moden 3ashn yb2a right trinagle

}



ll fact[1000006], inv[1000006];



ll fp(ll base, ll exp)

{

	if (exp == 0)

		return 1;

	ll ans = fp(base, exp / 2);

	ans = (ans * ans) % mod;

	if (exp % 2 != 0)

		ans = (ans * (base % mod)) % mod;

	return ans;

}



void calcFacAndInv(ll n)

{

	fact[0] = inv[0] = 1;

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

	{

		fact[i] = (i * fact[i - 1]) % mod;

		inv[i] = fp(fact[i], mod - 2);

	}

}



ll ncr(ll n, ll r)

{

	return ((fact[n] * inv[r]) % mod * inv[n - r]) % mod;

}



ll npr(ll n, ll r)

{

	return (fact[n] * inv[n - r]) % mod;

}













	int dpa[100005], dpb[100005], dpc[100005];

int main()

{

	ll n,arr[100005],a,b,c;

	char tmp;

	cin >> n;

	

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

		cin >> dpa[i] >> dpb[i] >> dpc[i];

	}

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

		dpa[i] += max(dpb[i - 1], dpc[i - 1]);

		dpb[i] += max(dpa[i-1], dpc[i-1]);

		dpc[i] += max(dpb[i-1], dpa[i-1]);

	}

	cout << max(dpa[n - 1], max(dpb[n - 1], dpc[n - 1]));



	return 0;

}