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

#include <iostream>

using namespace std;

const int MAXN=1e5+7;

int n,ans;

int h[MAXN][5],f[MAXN][5][5];

int main()

{

	cin>>n;

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

		cin>>h[i][1]>>h[i][2]>>h[i][3];

	memset(f,127,sizeof(f));

	for(int i=1;i<=3;i++)

		for(int j=1;j<=3;j++) f[1][i][j]=h[1][i];

	for(int i=2;i<=n;i++)

		for(int j=1;j<=3;j++)

			for(int k=1;k<=3;k++)

			{

				int maxx=0;

				for(int l=1;l<=3;l++)

					if(j!=k&&k!=l) maxx=max(maxx,f[i-1][k][l]);

				f[i][j][k]=maxx+h[i][j];

			}

	for(int i=1;i<=3;i++)

		for(int j=1;j<=3;j++) ans=max(ans,f[n][i][j]);

	cout<<ans<<endl;

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 3.822367805443137x):
#include<bits/stdc++.h>

#include <ext/pb_ds/tree_policy.hpp>

#include <ext/pb_ds/assoc_container.hpp>



using namespace __gnu_pbds;

using namespace std;





template <typename T>using ordered_set = tree<T, null_type, less<T>,rb_tree_tag, tree_order_statistics_node_update>;



#define PI              acos(-1.0)

#define en '\n'

#define Infi 0x3f3f3f3f

#define LInfi 0x3f3f3f3f3f3f3f3f



#define setzero(a)    memset(a,0,sizeof(a))

#define setneg(a)     memset(a,-1,sizeof(a))

#define setinf(a)     memset(a,126,sizeof(a))





#define READ_IN freopen("Input.txt","r",stdin);

#define READ_OUT freopen("Output.txt","w",stdout);





const int dx[] = {+1,-1,+0,+0};                         // 4 X directions

const int dy[] = {+0,+0,+1,-1};                         // 4 Y directions

const int dx8[] = {+0,+0,+1,-1,-1,+1,-1,+1};            // King X Moves

const int dy8[] = {-1,+1,+0,+0,+1,+1,-1,-1};            // King Y Moves

const int kx[] = {-2, -2, -1, -1,  1,  1,  2,  2};      // Knight X Moves

const int ky[] = {-1,  1, -2,  2, -2,  2, -1,  1};      // Knight Y Moves







int  Set    (int N,int pos) {return N=N | (1<<pos);}    /// turn a bit on

int  reset  (int N,int pos) {return N= N & ~(1<<pos);}  /// turn a bit off

bool check  (int N,int pos) {return (bool)(N & (1<<pos));} /// check, if a bit is on or not



void __print(int x) {cerr << x;}

void __print(long x) {cerr << x;}

void __print(long long x) {cerr << x;}

void __print(unsigned x) {cerr << x;}

void __print(unsigned long x) {cerr << x;}

void __print(unsigned long long x) {cerr << x;}

void __print(float x) {cerr << x;}

void __print(double x) {cerr << x;}

void __print(long double x) {cerr << x;}

void __print(char x) {cerr << '\'' << x << '\'';}

void __print(const char *x) {cerr << '\"' << x << '\"';}

void __print(const string &x) {cerr << '\"' << x << '\"';}

void __print(bool x) {cerr << (x ? "true" : "false");}



template<typename T, typename V>

void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}

template<typename T>

void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}

void _print() {cerr << "]\n";}

template <typename T, typename... V>

void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}

#ifndef ONLINE_JUDGE

#define trace(x...) cerr << "[" << #x << "] = ["; _print(x)

#else

#define trace(x...)

#endif



typedef long long int  ll;

typedef unsigned long long int llu;



int dp[100005][5];



vector<vector<int>> vec;



int n;



int make(int pos, int id){



    if(pos==n)return 0;



    if(dp[pos][id]!=-1)return dp[pos][id];



    int ans = 0;



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

        if(id==i)continue;



        ans = max(ans , make(pos+1,i) + vec[pos][id]);

    }

    return dp[pos][id] = ans;

}





int main(void){



    cin >> n;



    vec.assign(n+1,vector<int>());



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

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

            int val;

            cin >> val;

            vec[i].push_back(val);

        }

    }



    memset(dp,-1,sizeof(dp));



    int ans = 0;



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

        ans = max(ans, make(0,i));

    }



    cout << ans << endl;



    return 0;

}