#define _GLIBCXX_DEBUG
#include<bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define FIO ios_base::sync_with_stdio(false);cin.tie(NULL);
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define mt make_tuple
#define ff first
#define ss second
#define vll vector<ll>
#define pll pair<ll,ll>
#define vpll vector<pll>
#define vvll vector<vll>
#define all(v) v.begin(),v.end()
#define itr(r,v) for(auto r=v.begin();r!=v.end();r++)
#define FOR(i,n) for(ll i=0;i<n;i++)
#define ffo(i,a,b) for(ll i=a;i<=b;i++)
#define rfr(i,a,b) for(ll i=a;i>=b;i--)
#define space cout<<"\n\n";
#define endl "\n"
#define pqmx priority_queue<ll>
#define pqmn priority_queue<ll,vll,greater<ll>>
#define fps(x,y) fixed<<setprecision(y)<<x
#define merg(a,b,c) set_union(a.begin(),a.end(),b.begin(),b.end(),inserter(c,c.begin()))
#define set_ar(arr,v) memset(arr,v,sizeof(arr))
#define ctime auto sttart = high_resolution_clock::now()
#define etime auto sttop = high_resolution_clock::now()
#define go_t ll testcases; cin>>testcases; for(ll caseno= 1 ;caseno <= testcases; caseno++)
#define ptime auto z1z = duration_cast<microseconds>(sttop-sttart); cout<<"\nTime taken : "<<z1z.count()<<" microseconds\n"
#define dbg1(x)             cout <<#x<<": "<<x<<'\n';
#define dbg2(x, y)          cout <<#x<<": "<<x<<" | "<<#y<<": "<<y<<'\n';
#define dbg3(x, y, z)       cout <<#x<<": "<<x<<" | "<<#y<<": "<<y<<" | "<<#z<<": "<<z<<'\n';
#define dbg4(a, b, c, d)    cout <<#a<<": "<<a<<" | "<<#b<<": "<<b<<" | "<<#c<<": "<<c<<" | "<<#d<<": "<<d<<'\n';
#define dbg5(a, b, c, d, e) cout <<#a<<": "<<a<<" | "<<#b<<": "<<b<<" | "<<#c<<": "<<c<<" | "<<#d<<": "<<d<<" | "<<#e<<": "<<e<<'\n';

using namespace std;
using namespace std::chrono;

const ll MOD = 1e9 + 7;
const ll N = 1e5 + 5;
const ll maxN = 1e5 + 5;
const ll MAX_SIZE = 2e6 + 6;
const ll INF = 0x3f3f3f3f3f3f3f3fll;
const double PI = 3.14159265359;

ll powerM(ll x, ll y, ll M = MOD) { // default argument
	ll v = 1; x = x % M; while (y > 0) {if (y & 1)v = (v * x) % M; y = y >> 1; x = (x * x) % M;} return v;
}

ll power(ll x, ll y) {
	ll v = 1; while (y > 0) {if (y & 1)v = v * x; y = y >> 1; x = x * x;} return v;
}

ll n, k;
ll a[maxN];
ll b[maxN];
ll c[maxN];
ll dp[maxN][3];

ll solve(ll pos, ll picked) { // picked is taken at pos
	if (pos == 0) {
		if (picked == 0) return dp[pos][0] = a[0];
		else if (picked == 1) return dp[pos][1] = b[0];
		else return dp[pos][2] = c[0];
	}
	//
	if (dp[pos][picked] != -1) return dp[pos][picked];
	//
	if (picked == 0) {
		return dp[pos][0] = a[pos] + max(dp[pos - 1][1] = dp[pos - 1][1] == -1 ? solve(pos - 1, 1) : dp[pos - 1][1],
		                                 dp[pos - 1][2] = dp[pos - 1][2] == -1 ? solve(pos - 1, 2) : dp[pos - 1][2]);
	}
	else if (picked == 1) {
		return dp[pos][1] = b[pos] + max(dp[pos - 1][0] = dp[pos - 1][0] == -1 ? solve(pos - 1, 0) : dp[pos - 1][0],
		                                 dp[pos - 1][2] = dp[pos - 1][2] == -1 ? solve(pos - 1, 2) : dp[pos - 1][2]);
	}
	else {
		return dp[pos][2] = c[pos] + max(dp[pos - 1][0] = dp[pos - 1][0] == -1 ? solve(pos - 1, 0) : dp[pos - 1][0],
		                                 dp[pos - 1][1] = dp[pos - 1][1] == -1 ? solve(pos - 1, 1) : dp[pos - 1][1]);
	}
}

int main()
{
#ifndef ONLINE_JUDGE
	freopen("input1.txt", "r", stdin);
	freopen("output1.txt", "w", stdout);
#endif
	FIO
	cin >> n;
	FOR(i, n) cin >> a[i] >> b[i] >> c[i];
	FOR(i, n) {
		FOR(j, 3) dp[i][j] = -1;
	}
	cout << max({solve(n - 1, 0), solve(n - 1, 1), solve(n - 1, 2)});
	return 0;
}


Measured memory_bytes: 12936