// Slower C++ solution:
#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;

}


// Faster C++ solution for the same problem (measured speedup: 2.9723068958284173x):
#include<bits/stdc++.h>

using namespace std;

//#pragma gcc optimize("O3")

//#pragma gcc optimize("unroll-loops")

#ifdef EVAH

    #define _WIN32_WINNT 0x0500

    //#include<windows.h>

#endif

#define openFile(n) ShellExecute(nullptr,"open",n,nullptr,nullptr,SW_SHOWNORMAL);

#define closeP(n) system((string("taskkill /im ")+n+" /f").c_str());

#define closeConsole PostMessage(GetConsoleWindow(), WM_CLOSE, 0, 0);

#define opf "output.txt"

#define ipf "input.txt"

#define mem(n,x) memset(n,x,sizeof(n));

#define sf scanf

#define pf printf

#define ff first

#define ss second

#define pb push_back

#define PII pair<int,int>

#define PLL pair<LL,LL>

#define For(x,n) for(int i=x; i<n; i++)

#define stv v+2*(mid-tl+1)

#define LL long long int

#define N 100001



LL dp1[N],dp2[N],dp3[N];



int main() {

    ios_base::sync_with_stdio(false);

    cin.tie(nullptr); cout.tie(nullptr);

    #ifdef EVAH

        //freopen(ipf,"r",stdin);

        //openFile(ipf);

        //closeConsole;

        //freopen(opf,"w",stdout);

    #endif



    LL n;

    cin >> n;

    vector<LL> one(n),two(n),three(n);

    For(0,n) cin >> one[i] >> two[i] >> three[i];

    dp1[0]=one[0],dp2[0]=two[0],dp3[0]=three[0];

    For(1,n) {

        dp1[i] = one[i]+max(dp2[i-1],dp3[i-1]);

        dp2[i] = two[i]+max(dp1[i-1],dp3[i-1]);

        dp3[i] = three[i]+max(dp1[i-1],dp2[i-1]);

    }

    cout << max(dp1[n-1],max(dp2[n-1],dp3[n-1])) << "\n";



    #ifdef EVAH

        //openFile(opf);

        //Sleep(3000);

        //closeP("notepad.exe");

        //closeConsole;

    #endif

}