stablegradients/pie-gem5-pairs huggingface dataset:
// Slower C++ solution:
#include <bits/stdc++.h>

using namespace std;

int n;

int arr[100005][3];



int dp[100005][4];



int solve(int i, int prev){

	if(i == n) return 0;

	if(dp[i][prev] != -1) return dp[i][prev];



	dp[i][prev] = -1e7;

	int a = 0, b = 0, c = 0;

	if(prev != 0)

		a = solve(i+1, 0) + arr[i][0];

	if(prev != 1)

		b = solve(i+1, 1) + arr[i][1];

	if(prev != 2)

		c = solve(i+1, 2) + arr[i][2];



	dp[i][prev] = max(a, max(b, c));

	return dp[i][prev];

}



int main(){

	cin>>n;

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

		cin>>arr[i][0]>>arr[i][1]>>arr[i][2];



	memset(dp, -1, sizeof dp);

	cout<<solve(0, 3)<<endl;

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 2.596524061644982x):
#include<bits/stdc++.h>

#define MAXN 1e5



using namespace std;





int dp (){

}



long long n,m,a,b,c,k;

string s1,s2;



int main(){

    cin>>n;

    int l[n][3];

    cin>>l[0][0]>>l[0][1]>>l[0][2];

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

        cin>>l[i][0]>>l[i][1]>>l[i][2];

        l[i][0]+=max(l[i-1][1], l[i-1][2]);

        l[i][1]+=max(l[i-1][0], l[i-1][2]);

        l[i][2]+=max(l[i-1][1], l[i-1][0]);

    }

    cout<<max(l[n-1][0], max(l[n-1][1], l[n-1][2]))<<endl;

}
// Slower C++ solution:
#define _CRT_SECURE_NO_WARNINGS

#include<iostream>

#include<functional>

#include <bitset>

#include<algorithm>

#include<fstream>

#include<string>

#include <cstring>

#include<stdio.h>

#include<iomanip>

#include<sstream>

#include<cmath>

#include<vector>

#include<assert.h>

#include<queue>

#include<deque>

#include<stack>

#include<set>

#include<map>

// never lose hope ..

typedef unsigned long long ull;

typedef long long ll;

typedef long double ld;

#define eps 1e-8

using namespace std;

double const  PI = 3.141592653;

const int OO = 1000000000 + 9;



void fast() {

	ios_base::sync_with_stdio(0);

	cin.tie(NULL), cout.tie(NULL);

}

struct s {

	int x, y, z;

};



int n;

int v[(int)1e5][4];

int dp[(int)1e5][4];



int solve(int i = 0, int pre = 4) {

	if (i >= n)return 0;

	if (dp[i][pre] != -1)return dp[i][pre];

	int ch1, ch2, ch3;

	ch1 = ch2 = ch3 = 0;

	if (pre != 1) {

		ch1 += solve(i + 1, 1) + v[i][1];

	}

	if (pre != 2) {

		ch2 += solve(i + 1, 2) + v[i][2];

	}

	if (pre != 3) {

		ch3 += solve(i + 1, 3) + v[i][3];

	}

	return dp[i][pre] = max({ ch1,ch2,ch3 });

}





int main()

{

	fast();



	cin >> n;

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

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

	}

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

	cout << solve();



	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 2.6082301064790867x):
#include<bits/stdc++.h>

#define MAXN 1e5



using namespace std;





int dp (){

}



long long n,m,a,b,c,k;

string s1,s2;



int main(){

    cin>>n;

    int l[n][3];

    cin>>l[0][0]>>l[0][1]>>l[0][2];

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

        cin>>l[i][0]>>l[i][1]>>l[i][2];

        l[i][0]+=max(l[i-1][1], l[i-1][2]);

        l[i][1]+=max(l[i-1][0], l[i-1][2]);

        l[i][2]+=max(l[i-1][1], l[i-1][0]);

    }

    cout<<max(l[n-1][0], max(l[n-1][1], l[n-1][2]))<<endl;

}
// Slower C++ solution:
#include <iostream>

#include<bits/stdc++.h>

using namespace std;



typedef long long ll;



int n;

int a[100005][4];

ll dp[100005][4];



ll solve(int d,int l){

    if(d==n+1) return 0;

    if(dp[d][l]!=-1) return dp[d][l];

    ll ret=0;

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

        if(i!=l){

            ret=max(ret, solve(d+1,i)+a[d][i]);

        }

    }

    return dp[d][l]=ret;



}





int main()

{

    cin>>n;

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

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

            cin>>a[i][j];

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

    cout<<solve(1,-1);



    return 0;

}


// Faster C++ solution for the same problem (measured speedup: 4.200690285289898x):
#include<bits/stdc++.h>

#define MAXN 1e5



using namespace std;





int dp (){

}



long long n,m,a,b,c,k;

string s1,s2;



int main(){

    cin>>n;

    int l[n][3];

    cin>>l[0][0]>>l[0][1]>>l[0][2];

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

        cin>>l[i][0]>>l[i][1]>>l[i][2];

        l[i][0]+=max(l[i-1][1], l[i-1][2]);

        l[i][1]+=max(l[i-1][0], l[i-1][2]);

        l[i][2]+=max(l[i-1][1], l[i-1][0]);

    }

    cout<<max(l[n-1][0], max(l[n-1][1], l[n-1][2]))<<endl;

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

using namespace std;



typedef long double LD;

typedef long long ll;

typedef map<int,int> mii;

typedef pair<int,int> pii;

typedef vector<pii> vpii;



#define pb              push_back

#define mp              make_pair

#define F               first

#define S               second

#define mod             1000000007

#define INF             2147483647

#define Endl            "\n"

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

#define precision(a)    cout << fixed << setprecision(a)

#define bug(a,b)        cout<<a<<"\t"<<b<<"\n";

#define Case(a,b)       cout<<"Case "<<a<<": "<<b<<"\n";

#define reset(a,b)      memset(a,b,sizeof(a));

#define srt(a)      sort(a.begin(),a.end());



const int MAXN = 1000005;

const int SQRTN = 1003;

const int LOGN = 22;

const double PI=acos(-1);

const int sz=1e5+9;



int strtoint(string str){

    stringstream ss(str);

    int x = 0;

    ss >> x ;

    return x ;

}

string intostr(int x){

    stringstream ss;

    ss << x;

    string str = ss.str();

    return str;

}

void rem(string &s, const string &c) {

	auto pos = s.find(c);

	if (pos == string::npos) {

		cout << -1 << endl;

		exit(0);

	}

	s.erase(0, pos + 1);

}

void println (int n){

    cout<<n<<"\n";

}

void printvec(vector <int> &a){

    for (int i=0;i<a.size();i++){

        cout<<a[i]<<" ";

    }

    cout<<"\n";

}



void printgraph(vector <int> g[],int e){

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

        cout<<i<<" --> ";

        for (int j=0;j<g[i].size();j++){

            cout<<g[i][j]<<" ";

        }

        cout<<"\n";

    }

}



void printmap (map <int,int> &mymap){

    for (auto itr = mymap.begin(); itr != mymap.end(); ++itr) {

        cout << '\t' << itr->first

             << '\t' << itr->second << '\n';

    }

    cout << "\n";

}



int a[100005][4], dp[100005][4];

int N;



int rec(int pos, int type){



    if(pos>N) return 0;



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



    int ret = -1;

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

        if(i!=type)

            ret = max (ret, rec(pos+1,i) + a[pos+1][i]);



    return dp[pos][type] = ret;

}





void solve(){

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

    int i,j;

    cin>>N;

    for(i=1; i<=N; i++)

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

            cin>>a[i][j];





   cout<< rec(0,0) << "\n";



    //printvec(v);

}





int main(){

    //FasterIO;



    solve();

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 2.6173807215899556x):
#include<bits/stdc++.h>

#define MAXN 1e5



using namespace std;





int dp (){

}



long long n,m,a,b,c,k;

string s1,s2;



int main(){

    cin>>n;

    int l[n][3];

    cin>>l[0][0]>>l[0][1]>>l[0][2];

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

        cin>>l[i][0]>>l[i][1]>>l[i][2];

        l[i][0]+=max(l[i-1][1], l[i-1][2]);

        l[i][1]+=max(l[i-1][0], l[i-1][2]);

        l[i][2]+=max(l[i-1][1], l[i-1][0]);

    }

    cout<<max(l[n-1][0], max(l[n-1][1], l[n-1][2]))<<endl;

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

#define inf INFINITY

#define file freopen( "input.txt" , "r" , stdin) ; freopen( "output.txt" , "w" , stdout) ;

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

#define _3102_ main()

#define endl '\n'

typedef long long ll;

typedef unsigned long long ull;

typedef long double ld;

using namespace std;

const int N = 1e5 + 100;

const ll MX = 1e9;

const ll mod = 1e9 + 7;

const double eps = 1e-9 ;



ll n, a[N] , b[N] , c[N], dp[N][3] ;



ll solve( int i , int j ){

	if ( i < 0 ) return 0 ;

	ll &ret = dp[i][j] ;

	if ( ret != -1) return ret ;

	if ( j == 0 ){

		return ret = a[i] + max ( solve(i-1 , 1), solve(i-1,2) ) ;

	}

	else if ( j == 1 ){

		return ret = b[i] + max ( solve(i-1 , 0), solve(i-1,2) ) ;

	}

	return ret = c[i] + max ( solve(i-1 , 1), solve(i-1,0) ) ;

}



int _3102_{

	Gamed

	cin >> n ;

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

		cin >> a[i] >> b[i] >> c[i] ;

	}

	memset ( dp , -1 , sizeof dp);

	dp[0][0] = a[0] , dp[0][1] = b[0] , dp[0][2] = c[0] ;

	cout << max ( solve ( n - 1 , 1) , max ( solve ( n -1 , 0 ) , solve ( n - 1 , 2 ))) << endl ;

	return 0;

}


// Faster C++ solution for the same problem (measured speedup: 3.404521585730066x):
#include<bits/stdc++.h>

#define MAXN 1e5



using namespace std;





int dp (){

}



long long n,m,a,b,c,k;

string s1,s2;



int main(){

    cin>>n;

    int l[n][3];

    cin>>l[0][0]>>l[0][1]>>l[0][2];

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

        cin>>l[i][0]>>l[i][1]>>l[i][2];

        l[i][0]+=max(l[i-1][1], l[i-1][2]);

        l[i][1]+=max(l[i-1][0], l[i-1][2]);

        l[i][2]+=max(l[i-1][1], l[i-1][0]);

    }

    cout<<max(l[n-1][0], max(l[n-1][1], l[n-1][2]))<<endl;

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

using namespace std;

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

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

typedef long long ll;

typedef unsigned long long ull;

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

#define forr(i, a, b) for(ll i = (a); i < (ll) (b); i++)

#define forn(i, n) forr(i, 0, n)

#define pb push_back

#define mp make_pair

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

#define DBG(x) cerr << #x << " = " << (x) << endl

#define MOD 1000000007

#define MAXN 100005

ll dp[MAXN][3];

void solve(vector< vector<ll> > &a, int n)

{

    forn(i,MAXN)

    {

        forn(j,3)

        {

            dp[i][j]=(pow(10,9)+5)*(ll)(-1);

        }

    }

    dp[0][0]=a[0][0], dp[0][1]=a[0][1], dp[0][2]=a[0][2];

    forr(i,1,n)

    {

        forn(j,3)

        {

            forn(k,3)

            {

                if(j==k)

                {

                    continue;

                }

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

            }

        }

 

    }

    cout << max(dp[n-1][0],max(dp[n-1][1],dp[n-1][2])) << "\n";

}

 

int main() {

    FIN;

    int n;

    cin >> n;

    vector< vector<ll> > arreglo(n);

    forn(i,n) arreglo[i].resize(3);

    forn(i,n)

    {

        forn(j,3) cin >> arreglo[i][j];

    }

    solve(arreglo, n);

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 3.4076759125171776x):
#include<bits/stdc++.h>

#define MAXN 1e5



using namespace std;





int dp (){

}



long long n,m,a,b,c,k;

string s1,s2;



int main(){

    cin>>n;

    int l[n][3];

    cin>>l[0][0]>>l[0][1]>>l[0][2];

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

        cin>>l[i][0]>>l[i][1]>>l[i][2];

        l[i][0]+=max(l[i-1][1], l[i-1][2]);

        l[i][1]+=max(l[i-1][0], l[i-1][2]);

        l[i][2]+=max(l[i-1][1], l[i-1][0]);

    }

    cout<<max(l[n-1][0], max(l[n-1][1], l[n-1][2]))<<endl;

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

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

#define ll long long

using namespace std;

const int N = 100010;

int dp[N][3];

int main(){

    fast;

	int n, i, a, b, c;

	cin >> n;

	memset(dp, 0, sizeof dp);

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

		cin >> a >> b >> c;

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

		dp[i + 1][1] = b + max(dp[i][0], dp[i][2]);

		dp[i + 1][2] = c + max(dp[i][0], dp[i][1]);

	}

	cout << max(dp[n][0], max(dp[n][1], dp[n][2])) << "\n";

	return 0;

}


// Faster C++ solution for the same problem (measured speedup: 2.2140902710007357x):
#include<bits/stdc++.h>

#define MAXN 1e5



using namespace std;





int dp (){

}



long long n,m,a,b,c,k;

string s1,s2;



int main(){

    cin>>n;

    int l[n][3];

    cin>>l[0][0]>>l[0][1]>>l[0][2];

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

        cin>>l[i][0]>>l[i][1]>>l[i][2];

        l[i][0]+=max(l[i-1][1], l[i-1][2]);

        l[i][1]+=max(l[i-1][0], l[i-1][2]);

        l[i][2]+=max(l[i-1][1], l[i-1][0]);

    }

    cout<<max(l[n-1][0], max(l[n-1][1], l[n-1][2]))<<endl;

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

using namespace std;

#define tpl  tuple<int, int, int>

#define mt   make_tuple

#define LIM  100000





int n, dp[LIM+5][4], vis[LIM+5][4];

vector<tpl> v;



int f(int pos, int k){

    if(pos >= n) return 0;

    if(vis[pos][k]) return dp[pos][k];

    vis[pos][k] = 1;

    int ans;

    if(k == 0) ans = get<0>(v[pos]) + max(f(pos+1, 1), f(pos+1, 2));

    else if(k == 1) ans = get<1>(v[pos]) + max(f(pos+1, 0), f(pos+1, 2));

    else ans = get<2>(v[pos]) + max(f(pos+1, 0), f(pos+1, 1));



    return dp[pos][k] = ans;

}



int main(){

    scanf("%d", &n);

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

        int a, b, c; scanf("%d %d %d", &a, &b, &c);

        v.push_back(mt(a, b, c));

    }

    int ans = f(0, 0);

    memset(dp, 0, sizeof dp);

    memset(vis, 0, sizeof vis);

    ans = max(ans, f(0, 1));

    memset(dp, 0, sizeof dp);

    memset(vis, 0, sizeof vis);

    ans = max(ans, f(0, 2));



    printf("%d\n", ans);

}


// Faster C++ solution for the same problem (measured speedup: 1.2857150993811628x):
#include <bits/stdc++.h>

#define ll long long

#define endl "\n"

#define shalaby ios::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);cerr.tie(0);

#define mod 100000000

using namespace std;



inline int D()

{

    int t;

    scanf("%d",&t);

    return t;

}

inline ll llD()

{

    ll t;

    scanf("%lld",&t);

    return t;

}

const int Max=1e5+8;

const int OO=-1e6;

int xt[4]= {1,0,0,-1};

int yt[4]= {0,1,-1,0};

////////////////////////////////////////////////////////////////////////////////////



ll mem[100005][5],a[100005],b[100005],c[100005],n,m;

bool valid(int x,int y)

{

    return x>-1 && y>-1 && x<n && y<m;

}

void init()

{

    memset(mem,-1,sizeof mem);

}

/////////////////////////////////////////////////////////////////////

ll solve(int i=0, int k=3)

{

    if(i==n)

        return 0;

    ll &ret=mem[i][k];

    if(~ret)return ret;

    ret =0;

    if(k!=0)

        ret=max(ret,solve(i+1,0)+a[i]);



    if(k!=1)

        ret=max(ret,solve(i+1,1)+b[i]);

    if(k!=2)

        ret=max(ret,solve(i+1,2)+c[i]);

    return ret;

}



int main()

{

    init();

    int T=1;

///   T=D();

    while(T-->0)

    {

        cin >> n ;

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

        {

            cin >> a[i] >> b[i]>>c[i];

        }

        cout << solve();

    }

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

using namespace std;



long long w1,w2,hap=0,maxi,aa,bb,cc,N,i,j,k,a[100005][5];

long long M[100005][5];





int main()

{

    ios_base::sync_with_stdio(false);

    cin.tie(NULL);

    cin>>N;

    for(i=0; i<100003; i++)

        for(j=0; j<4; j++)

            M[i][j]=0;



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

        cin>>a[i][0]>>a[i][1]>>a[i][2];

    M[N-1][0]=a[N-1][0];

    M[N-1][1]=a[N-1][1];

    M[N-1][2]=a[N-1][2];



    for(i=N-2; i>=0; i--)

    {

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

        {

            if(j==0)

            {

                w1=1;

                w2=2;

            }

            else if(j==1)

            {

                w1=0;

                w2=2;

            }

            else

            {

                w1=0;

                w2=1;

            }

        M[i][j]=a[i][j]+max(M[i+1][w1],M[i+1][w2]);

        }

    }

    aa=max(M[0][0],M[0][1]);

    aa=max(aa,M[0][2]);

    cout<<aa<<endl;

    return 0;

}






// Faster C++ solution for the same problem (measured speedup: 4.997933668609778x):
#include<bits/stdc++.h>



typedef   long long  int ll;

typedef  long double ld;

typedef std::vector<ll> vi;

typedef std::vector<std::vector<ll> > vv;



#define MOD 1000000007

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

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

#define mp make_pair

#define pb(x) push_back(x)

#define fi first

#define se second

#define print(vec,a,b) for(ll i=a;i<b;i++) cout<<vec[i]<<" ";cout<<endl;

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

#define input(vec,a,b) for(ll i = a;i<b;i++) cin>>vec[i];

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

using namespace std;



const int N = 1e5 + 5;





void solve(){

            ll i,j,n,m,k;

            

            

            cin>>n;

            ll dp[n][3];

            ms(dp,0);

            ll a[n][3];

            fo(i,0,n)

            {fo(j,0,3)

				cin>>a[i][j];

			}

			fo(i,0,3)

			dp[0][i] = a[0][i];//,dp[1] = a[1],dp[2]  =a[2];

			fo(i,1,n)

			{

				fo(j,0,3)

				{

					//dp[i][j] = INT_MAX;

					fo(k,0,3)

					{

						if(j^k)

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

					 }

				 }

			 }

			 ll minn =  INT_MIN;

			 fo(i,0,3)

			  minn = max(minn,dp[n-1][i]);

			  cout<<minn<<endl;

            

    

            

						            



















}



int main()

{

    IO;

      ll t=1;

      //cin>>t;





      while(t--)

      {



          solve();

      }

    return 0;

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

using namespace std;

#define INF 100005

#define maxx 1000000000000



int n;

long long a[INF][3];

long long mem[INF][3];



long long rec(int level,int pre)

{

    if(level==n) return 0;

    if(mem[level][pre]!=-1) return mem[level][pre];

    long long now=0;

    if(pre==0)

    {

        now=max(now,max(a[level][0]+rec(level+1,1),a[level][0]+rec(level+1,2)));

    }else

    if(pre==1)

    {

        now=max(now,max(a[level][1]+rec(level+1,0),a[level][1]+rec(level+1,2)));

    }else

    if(pre==2)

    {

        now=max(now,max(a[level][2]+rec(level+1,0),a[level][2]+rec(level+1,1)));

    }

    return mem[level][pre]=now;

}



int main()

{

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

    scanf("%d",&n);

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

    {

        scanf("%lld%lld%lld",&a[i][0],&a[i][1],&a[i][2]);

    }

    long long ans=max(rec(0,0),max(rec(0,1),rec(0,2)));

    printf("%lld\n",ans);

}


// Faster C++ solution for the same problem (measured speedup: 3.35284987411242x):
#include<bits/stdc++.h>



typedef   long long  int ll;

typedef  long double ld;

typedef std::vector<ll> vi;

typedef std::vector<std::vector<ll> > vv;



#define MOD 1000000007

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

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

#define mp make_pair

#define pb(x) push_back(x)

#define fi first

#define se second

#define print(vec,a,b) for(ll i=a;i<b;i++) cout<<vec[i]<<" ";cout<<endl;

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

#define input(vec,a,b) for(ll i = a;i<b;i++) cin>>vec[i];

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

using namespace std;



const int N = 1e5 + 5;





void solve(){

            ll i,j,n,m,k;

            

            

            cin>>n;

            ll dp[n][3];

            ms(dp,0);

            ll a[n][3];

            fo(i,0,n)

            {fo(j,0,3)

				cin>>a[i][j];

			}

			fo(i,0,3)

			dp[0][i] = a[0][i];//,dp[1] = a[1],dp[2]  =a[2];

			fo(i,1,n)

			{

				fo(j,0,3)

				{

					//dp[i][j] = INT_MAX;

					fo(k,0,3)

					{

						if(j^k)

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

					 }

				 }

			 }

			 ll minn =  INT_MIN;

			 fo(i,0,3)

			  minn = max(minn,dp[n-1][i]);

			  cout<<minn<<endl;

            

    

            

						            



















}



int main()

{

    IO;

      ll t=1;

      //cin>>t;





      while(t--)

      {



          solve();

      }

    return 0;

}
// Slower C++ solution:
#include<cstdio>

#include<algorithm>

#include<cstring>

using namespace std;

const int maxn = 1e5 + 5;



int a[maxn][4];

int dp[maxn][4];//d[i][j] i day choose j thing 's max happy



int main(){

	int n;scanf("%d",&n);

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

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

			scanf("%d",&a[i][j]);

		}

	}



	memset(dp, 0, sizeof dp);



	for(int i = 1 ; i <= 3 ; i++) dp[1][i] = a[1][i];



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

		dp[i][1] = max(dp[i - 1][2] ,dp[i - 1][3]) + a[i][1];

		dp[i][2] = max(dp[i - 1][1] ,dp[i - 1][3]) + a[i][2];

		dp[i][3] = max(dp[i - 1][2] ,dp[i - 1][1]) + a[i][3];

	}



	int ans = 0;

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

	printf("%d\n",ans);

}

// Faster C++ solution for the same problem (measured speedup: 1.767759183282868x):
#include<bits/stdc++.h>



typedef   long long  int ll;

typedef  long double ld;

typedef std::vector<ll> vi;

typedef std::vector<std::vector<ll> > vv;



#define MOD 1000000007

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

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

#define mp make_pair

#define pb(x) push_back(x)

#define fi first

#define se second

#define print(vec,a,b) for(ll i=a;i<b;i++) cout<<vec[i]<<" ";cout<<endl;

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

#define input(vec,a,b) for(ll i = a;i<b;i++) cin>>vec[i];

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

using namespace std;



const int N = 1e5 + 5;





void solve(){

            ll i,j,n,m,k;

            

            

            cin>>n;

            ll dp[n][3];

            ms(dp,0);

            ll a[n][3];

            fo(i,0,n)

            {fo(j,0,3)

				cin>>a[i][j];

			}

			fo(i,0,3)

			dp[0][i] = a[0][i];//,dp[1] = a[1],dp[2]  =a[2];

			fo(i,1,n)

			{

				fo(j,0,3)

				{

					//dp[i][j] = INT_MAX;

					fo(k,0,3)

					{

						if(j^k)

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

					 }

				 }

			 }

			 ll minn =  INT_MIN;

			 fo(i,0,3)

			  minn = max(minn,dp[n-1][i]);

			  cout<<minn<<endl;

            

    

            

						            



















}



int main()

{

    IO;

      ll t=1;

      //cin>>t;





      while(t--)

      {



          solve();

      }

    return 0;

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



using namespace std;



    const int n = 1e5+5;

    int num;

    int act[n][3];

    int dyn[3][n];

    

    int init(int a, int i){

        

    	if(i == num) return 0;

    	

    	if(dyn[a][i] != -1) return dyn[a][i];

    	int& res = dyn[a][i];

    	

    	if(a==0){

    	    

    		res=max(res, init(1, i+1)+act[i][0]);

    		res=max(res, init(2, i+1)+act[i][0]);

    	}

    	

    	if(a==1){

    	    

    		res=max(res, init(0, i+1)+act[i][1]);

    		res=max(res, init(2, i+1)+act[i][1]);

    	}

    	

    	if(a==2){

    	    

    		res=max(res, init(0, i+1)+act[i][2]);

    		res=max(res, init(1, i+1)+act[i][2]);

    	}

    	

    	

    	return res;

    }

    

    int main(){

        

    	cin>>num;

    	for(int i=0; i<num; i++) cin>>act[i][0]>>act[i][1]>>act[i][2];

    	memset(dyn, -1, sizeof dyn);

    	cout<<max(init(0,0),max(init(1,0),init(2,0)))<<"\n";

    	return 0;

    	

    }

// Faster C++ solution for the same problem (measured speedup: 2.1823339734798557x):
#include<bits/stdc++.h>



typedef   long long  int ll;

typedef  long double ld;

typedef std::vector<ll> vi;

typedef std::vector<std::vector<ll> > vv;



#define MOD 1000000007

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

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

#define mp make_pair

#define pb(x) push_back(x)

#define fi first

#define se second

#define print(vec,a,b) for(ll i=a;i<b;i++) cout<<vec[i]<<" ";cout<<endl;

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

#define input(vec,a,b) for(ll i = a;i<b;i++) cin>>vec[i];

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

using namespace std;



const int N = 1e5 + 5;





void solve(){

            ll i,j,n,m,k;

            

            

            cin>>n;

            ll dp[n][3];

            ms(dp,0);

            ll a[n][3];

            fo(i,0,n)

            {fo(j,0,3)

				cin>>a[i][j];

			}

			fo(i,0,3)

			dp[0][i] = a[0][i];//,dp[1] = a[1],dp[2]  =a[2];

			fo(i,1,n)

			{

				fo(j,0,3)

				{

					//dp[i][j] = INT_MAX;

					fo(k,0,3)

					{

						if(j^k)

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

					 }

				 }

			 }

			 ll minn =  INT_MIN;

			 fo(i,0,3)

			  minn = max(minn,dp[n-1][i]);

			  cout<<minn<<endl;

            

    

            

						            



















}



int main()

{

    IO;

      ll t=1;

      //cin>>t;





      while(t--)

      {



          solve();

      }

    return 0;

}