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

using namespace std;

// Macros for easier access

#define ll long long

#define umap unordered_map

#define uset unordered_set

#define test ll cases; cin>>cases; for(ll testCase = 1; testCase <= cases; testCase++)   //test cases

#define rep(i, begin, end, upd)  for(ll i = begin; ((begin < end && upd > 0 && i < end) || (begin > end && upd < 0 && i >= end)); i+=upd)

#define fill(name, val) memset(name, val, sizeof(name));

#define mop(a, op, b)	(a%mod op b%mod)%mod

#define error(x) fixed<<setprecision(x) //cout<<error(5)<<someDouble    -> example - 3.14159

#define vll vector<ll>

#define vvll vector<vll>

#define pll pair<ll, ll>

#define get(array) for(ll index = 0; index < sizeof(array)/sizeof(array[0]); index++) cin>>array[index];

#define boost ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)

#define debug(x) cerr << #x << " : " << (x) << endl

// Constants

#define MX 100001

#define mod 1000000007LL

#define inf 1000000000000000000LL

ll gcd(ll a, ll b){

	while(b){

		a %= b;

		swap(a, b);

	}

	return a;

}

ll power(ll x, ll n){

	x %= mod;	ll res = 1;

	while(n){

		if(n&1)	res = mop(res, *, x);

		x = mop(x, *, x);

		n >>= 1;

	}

	return res;

}

ll fermatInv(ll x){

    if(gcd(x, mod) != 1)  return -1;

    return power(x, mod-2);

}

vll primeSieve(ll n = MX){

	vll primes;

    bool nums[n];   fill(nums, true);

    primes.push_back(2);

    rep(i, 4, n, 2)   nums[i] = false;

    rep(i, 3, n, 2){

        if(nums[i]){

            primes.push_back(i);

            rep(j, i*i, n, i) nums[j] = false;

        }

    }

	return primes;

}

vll factorize(ll n){

    vll res;

    ll rootn = sqrt(n);

    rep(i, 1, rootn+1, 1){

        if(n % i == 0){

            res.push_back(i);

            if(n/i != i)    res.push_back(n/i);

        }

    }

    return res;

}

vvll idMatrix(ll n){

	vvll id;

	rep(i, 0, n, 1){

		id.push_back({});

		rep(j, 0, n, 1)

			id[i].push_back(i==j);

	}

	return id;

}

vvll matrixMult(vvll mx1, vvll mx2){

	ll r = mx1.size(), c1 = mx2.size(), c = mx2[0].size();

	vvll result(r);

	rep(i, 0, r, 1)

		rep(j, 0, c, 1){

			ll sum = 0;

			rep(k, 0, c1, 1)

				sum = mop(sum, +, mop(mx1[i][k], *, mx2[k][j]));

			result[i].push_back(sum);

		}

	return result;

}

vvll matrixExpo(vvll matrix, ll n){

	if(n == 0)	return idMatrix(matrix.size());

	vvll sa = matrixExpo(matrix, n/2);

	sa = matrixMult(sa, sa);

	if(n & 1)	return matrixMult(sa, matrix);

	else		return sa;

}

ll nCr(ll n, ll r){

	if(r == 0)	return 1;

	ll f[n+1];	f[0] = 1;

	for(ll i = 1; i <= n; i++)	f[i] = mop(f[i-1], *, i);

	return mop(f[n], *, mop(fermatInv(f[r]), *, fermatInv(f[n-r])));

}

ll nCrDP(ll n, ll r, ll p){

	r = min(r, n - r);

	ll C[r+1];	fill(C, 0);

	C[0] = 1;

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

		for(ll j = min(i, r); j > 0; j--)

			C[j] = (C[j] + C[j-1]) % p;

	return C[r];

}

ll smallpnCr(ll n, ll r, ll p){

	if(r == 0)	return 1;

	ll ni = n % p, ri = r % p;

	return (smallpnCr(n/p, r/p, p) * nCrDP(ni, ri, p)) % p;

}

ll linearRec(vll f, vll c, ll n){

	ll order = f.size();

	vvll T = idMatrix(order);

	for(ll i = 0; i < order-1; i++)

		for(ll j = 0; j < order; j++)

			T[i][j] = T[i+1][j];

	for(ll i = 0; i < order; i++)	T[order-1][i] = c[i];

	T = matrixExpo(T, n - order);

	vvll f0;	for(auto x : f)	f0.push_back({x});

	T = matrixMult(T, f0);

	return T[order-1][0];

}

class TreeNode{

    public:

    ll val;

    TreeNode* left;

    TreeNode* right;

    TreeNode(ll v){

        val = v;

        left = right = NULL;

    }

};

class STree{

	public:

	ll n;

	ll* tree;

	ll queryBase;

	ll segOp(ll left, ll right);

	STree(ll arrLen, ll* arr, ll qb){	//build the tree

		n = arrLen;

		queryBase = qb;

		tree = new ll[2*n];

		rep(i, 0, n, 1)	tree[n+i] = arr[i];

		rep(i, n-1, 0, -1)	tree[i] = segOp(tree[i<<1], tree[i<<1|1]);

	}

	void update(ll index, ll value){	//point update

		for(tree[index += n] = value; index > 1; index >>= 1)	tree[index>>1] = segOp(tree[index], tree[index^1]);

	}

	ll query(ll left, ll right){	// [left, right)

		ll lres = queryBase, rres = queryBase;

		for(left += n, right += n; left < right; left >>= 1, right >>= 1){

			if(left&1) lres = segOp(lres, tree[left++]);

			if(right&1) rres = segOp(rres, tree[--right]);

		}

		return segOp(lres, rres);

	}

};

class Graph{

    ll N;

    bool weighted;

	bool directed;

    umap<ll, umap<ll, ll>> g; //(u, v, w) Assume all graphs are weighted. Unweighted => every edge weight = 1

	public:

	class Edge{

	public:

		ll u, v, w;

		Edge(ll U, ll V, ll W){

			tie(u, v, w) = tie(U, V, W);

		}

		bool operator<(Edge const& other){

			return w < other.w;

		}

	};

    Graph(ll n, bool w = false, bool d = false){

        N = n;

        weighted = w;

		directed = d;

    }

    auto addEdge(ll u, ll v, ll w = 1){

        g[u][v] = w;

		g[v];

		if(!directed)	g[v][u] = w;

    }

    auto printEdges(){

        for(auto u : g){

            cout<<u.first<<"-> ";

            for(auto v : u.second){

                cout<<v.first;

                if(weighted) cout<<"("<<v.second<<")";

                cout<<' ';

            }

            cout<<endl;

        }

    }

	auto dijkstra(ll src){

		umap<ll, ll> dist;

		set<pll> s;

		for(auto i : g)	dist[i.first] = inf;

		dist[src] = 0;

		s.insert({0, src});

		while(s.size()){

			pll temp = *(s.begin());

			s.erase(s.begin());

			ll u = temp.second;

			auto du = &dist[u];

			for(auto i : g[u]){

				ll v, w;

				tie(v, w) = i;

				auto dv = &dist[v];

				if(*dv > *du + w){

					if(*dv != inf)	s.erase(s.find({*dv, v}));

					*dv = *du + w;

					s.insert({*dv, v});

				}

			}

		}

		return dist;

	}

	auto flowar(){	// Floyd Warshall

		umap<ll, umap<ll, ll>> dist;

		vll nodes;

		for(auto x : g)	nodes.push_back(x.first);

		for(auto x : nodes)

			for(auto y : nodes)

				if(x == y)	dist[x][y] = 0;

				else if(g[x].find(y) == g[x].end())	dist[x][y] = inf;

				else	dist[x][y] = g[x][y];

		for(auto k : nodes)

			for(auto i : nodes)

				for(auto j : nodes)

					dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j]);

		return dist;

	}

	auto MST(){	//Kruskal's

		if(directed){

			cerr<<"Attempted Kruskal MST on directed graph!!!"<<endl;

			exit(0);

		}

		umap<ll, ll> parent;

		umap<ll, ll> rank;

		auto make_set = [&parent, &rank](ll v){

			parent[v] = v;

			rank[v] = 0;

		};

		function<ll(ll)> find_set;

		find_set = [&parent, &find_set](ll v) -> ll{

			if(v == parent[v])	return v;

			return parent[v] = find_set(parent[v]);

		};

		auto union_set = [&parent, &rank, &find_set](ll a, ll b){

			a = find_set(a);

			b = find_set(b);

			if(a == b)	return;

			if(rank[a] < rank[b])	swap(a, b);

			parent[b] = a;

			rank[a] += (rank[a] == rank[b]);

		};

		vector<Edge> edges;

		vector<Edge> mst;

		for(auto x : g){

			make_set(x.first);

			for(auto y : x.second){

				if(y.first < x.first){

					Edge e = Edge(x.first, y.first, y.second);

					edges.push_back(e);

				}

			}

		}

		sort(edges.begin(), edges.end());

		for(auto e : edges){

			if(find_set(e.u) != find_set(e.v)){

				mst.push_back(e);

				union_set(e.u, e.v);

			}

		}

		return mst;

	}

	auto dfs(ll curr, vll& res, uset<ll>& vis){

		if(vis.find(curr) != vis.end())	return;

		vis.insert(curr);

		for(auto x : g[curr])

			dfs(x.first, res, vis);

		res.push_back(curr);

	}

	auto toposort(){

		if(!directed){

			cerr<<"Toposort on bidirectional graph!!!";

			exit(0);

		}

		vll top;	uset<ll> vis;

		for(auto x : g)

			if(vis.find(x.first) == vis.end())

				dfs(x.first, top, vis);

		reverse(top.begin(), top.end());

		return top;

	}

};



/*  =======TL;DR=======

    Author : zenolus

    TreeNode (binary tree):

		TreeNode(v)   => create new node with val v

    Graph (Adjacency List representation):

		Graph(nodes, weighted = false, directed = false)  => create a graph with n nodes, specify if weighted

		addEdge(u, v, weight = 1)   => add an edge in graph, specify weight if necessary

		printEdges() => display the adjacency list

		dijkstra(src)	=> single src all dest shortest distance. returns a map <node, dist> Ot(ElogV) Os(V)	use AUTO

		flowar()	=> All pair shortest distance. returns 2D map <u, <v, d>>	Ot(V^3) Os(V^2)	use AUTO

		MST()	=> Returns the edge list containing N - 1 edges forming the Kruskal's MST	Ot(ElogE) Os(V+E)	use AUTO

		toposort()	=> returns dfs based topological sorted vector for DAGs		Ot(V+E) Os(V)	use AUTO

    STree (Segment Tree):

		STree(arrayLength, array, queryBase)	=> create the segment tree

		update(index, value)	=> point update

		query(left, right)	=> query segment operation on [l, r)

	Algorithms :

		gcd(a, b)   => returns gcd of a and b

		power(x, n) => return x raised to power n in O(log n) time, if required, specify modulo

		fermatInv(x)  => returns modular multiplicative inverse of x with mod

		primeSieve(n = MX)   => returns a vector of all the primes till n

		factorize(n)    => returns a vector of factors of n

		modMult(a, b)	=> returns (a*b)%mod

		idMatrix(matrix)	=> returns an identity matrix of dimensions similar to passed matrix

		matrixMult(A, B)	=> returns (A.B)%mod

		matrixExpo(A, n)	=> returns A power n % mod

		nCr(n, r)  => returns nCr value % mod using Fermat's theorem. O(n + log p)

		nCrDP(n, r, p)	=> returns nCr % p for small n, r, p	Ot(n*r), Os(n)

		smallnCr(n, r, p)	=> returns nCr % p for small p using Lucas' theorem.	Ot(p^2 + log n base p), Os(p)

		linearRec(f, c, n)	=> returns nth term of linear recurrence. F(n) = c1F(n-1) + c2F(n-2) + ... + ckF(n-k)

							Ex: linearRec({1, 2, 3}, {3, 4, 5}, 8)	=> starting terms 1, 2, 3. c1 = 5, c2 = 5, c3 = 3. k = 3

*/



ll STree::segOp(ll left, ll right){

	return left + right;	//Change per requirement

}



ll n;

ll A[MX], B[MX], C[MX];

ll dp[MX][4];

ll solve(ll i, ll pc = 0){

	if(i == n)	return 0;

	auto d = &dp[i][pc];

	if(*d != -1)	return *d;

	ll ans = 0;

	for(ll c = 1; c <= 3; c++){

		if(pc == c)	continue;

		ll val = c == 1 ? A[i] : c == 2 ? B[i] : c == 3 ? C[i] : 0;

		ans = max(ans, val + solve(i+1, c));

	}

	return *d = ans;

}

int main(){

	boost;

	cin>>n;

	for(ll i = 0; i < n; i++)	cin>>A[i]>>B[i]>>C[i];

	fill(dp, -1);

	cout<<solve(0);

}

// Faster C++ solution for the same problem (measured speedup: 4.188952982046841x):
#include <bits/stdc++.h>

using namespace std;

// Macros for easier access

#define ll long long

#define endl '\n'

#define umap unordered_map

#define uset unordered_set

#define test ll cases; cin>>cases; for(ll testCase = 1; testCase <= cases; testCase++)   //test cases

#define rep(i, begin, end, upd)  for(ll i = begin; ((begin < end && upd > 0 && i < end) || (begin > end && upd < 0 && i >= end)); i+=upd)

#define fill(name, val) memset(name, val, sizeof(name));

#define mop(a, op, b)    (a%mod op b%mod)%mod

#define error(x) fixed<<setprecision(x) //cout<<error(5)<<someDouble    -> example - 3.14159

#define vll vector<ll>

#define vvll vector<vll>

#define pll pair<ll, ll>

#define get(a, n)    for(ll i = 0; i < n; i++)    cin>>a[i];

#define boost ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);

#define debug(x) cerr << #x << " : " << (x) << endl

// Constants

#define MX 100001

#define mod 1000000007LL

#define inf 1000000000000000000LL

void init(){

	boost;

	#ifndef ONLINE_JUDGE

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

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

	#endif

}

/*  =======TL;DR=======

	Author : zenolus

	TreeNode (binary tree)[snippet key: tree]:

		TreeNode(v)   => create new node with val v

	Graph (Adjacency List representation)[snippet key: graph]:

		Graph(nodes, weighted = false, directed = false)  => create a graph with n nodes, specify if weighted

		addEdge(u, v, weight = 1)   => add an edge in graph, specify weight if necessary

		printEdges() => display the adjacency list

		dijkstra(src)    => single src all dest shortest distance. returns a map <node, dist> Ot(ElogV) Os(V)    use AUTO

		flowar()    => All pair shortest distance. returns 2D map <u, <v, d>>    Ot(V^3) Os(V^2)    use AUTO

		MST()    => Returns the edge list containing N - 1 edges forming the Kruskal's MST    Ot(ElogE) Os(V+E)    use AUTO

		toposort()    => returns dfs based topological sorted vector for DAGs        Ot(V+E) Os(V)    use AUTO

	SegTree (Segment Tree)[snippet key: segtree]:

		SegTree(arrayLength, array, queryBase)    => create the segment tree

		update(index, value)    => point update

		query(left, right)    => query segment operation on [l, r)

	Algorithms [snippet key: algo]:

		gcd(a, b)   => returns gcd of a and b

		power(x, n) => return x raised to power n in O(log n) time, if required, specify modulo

		fermatInv(x)  => returns modular multiplicative inverse of x with mod

		primeSieve(n = MX)   => returns a vector of all the primes till n

		factorize(n)    => returns a vector of factors of n

		modMult(a, b)    => returns (a*b)%mod

		idMatrix(matrix)    => returns an identity matrix of dimensions similar to passed matrix

		matrixMult(A, B)    => returns (A.B)%mod

		matrixExpo(A, n)    => returns A power n % mod

		nCr(n, r)  => returns nCr value % mod using Fermat's theorem. O(n + log p)

		nCrDP(n, r, p)    => returns nCr % p for small n, r, p    Ot(n*r), Os(n)

		smallnCr(n, r, p)    => returns nCr % p for small p using Lucas' theorem.    Ot(p^2 + log n base p), Os(p)

		linearRec(f, c, n)    => returns nth term of linear recurrence. F(n) = c1F(n-1) + c2F(n-2) + ... + ckF(n-k)

							Ex: linearRec({1, 2, 3}, {3, 4, 5}, 8)    => starting terms 1, 2, 3. c1 = 5, c2 = 5, c3 = 3. k = 3

*/



int main(){

	//init();

	boost;

	ll n;	cin>>n;	ll h[n+1][3];

	for(ll i = 1; i <= n; i++)	cin>>h[i][0]>>h[i][1]>>h[i][2];

	ll dp[2][3];	dp[0][0] = dp[0][1] = dp[0][2] = 0;

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

		dp[i%2][0] = h[i][0] + max(dp[(i-1)%2][1], dp[(i-1)%2][2]);

		dp[i%2][1] = h[i][1] + max(dp[(i-1)%2][0], dp[(i-1)%2][2]);

		dp[i%2][2] = h[i][2] + max(dp[(i-1)%2][1], dp[(i-1)%2][0]);

	}

	cout<<max({dp[n%2][0], dp[n%2][1], dp[n%2][2]});

}