stablegradients/pie-gem5-pairs huggingface dataset:
// 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: 4.267247007600548x):
#include <bits/stdc++.h>

using namespace std;

int main()

{

	int n;

	scanf("%d",&n);

	int a[3][n];

	long long b[3][n];

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

	{

		for(int t=0;t<3;t++)

		{

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

		}

	}

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

	{

		b[i][0]=a[i][0];

	}

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

	{

		for(int t=0;t<3;t++)

		{

			b[t][i]=0;

		}

	}

	for(int i=1;i<n;i++)//从第二行开始遍历 

	{

		for(int t=0;t<3;t++)//遍历该行的每个状态 

		{

			for(int j=0;j<3;j++)//遍历上一行的每个状态 

			{

				if(j==t)continue;

				b[t][i]=max(b[t][i],b[j][i-1]+a[t][i]);

			}

		}

	}

	long long mm=b[0][n-1];

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

	{

		if(mm<b[i][n-1])mm=b[i][n-1];

	}

	printf("%lld",mm);

	return 0;

}
// 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: 3.4584636243934592x):
#include <bits/stdc++.h>

using namespace std;

int main()

{

	int n;

	scanf("%d",&n);

	int a[3][n];

	long long b[3][n];

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

	{

		for(int t=0;t<3;t++)

		{

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

		}

	}

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

	{

		b[i][0]=a[i][0];

	}

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

	{

		for(int t=0;t<3;t++)

		{

			b[t][i]=0;

		}

	}

	for(int i=1;i<n;i++)//从第二行开始遍历 

	{

		for(int t=0;t<3;t++)//遍历该行的每个状态 

		{

			for(int j=0;j<3;j++)//遍历上一行的每个状态 

			{

				if(j==t)continue;

				b[t][i]=max(b[t][i],b[j][i-1]+a[t][i]);

			}

		}

	}

	long long mm=b[0][n-1];

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

	{

		if(mm<b[i][n-1])mm=b[i][n-1];

	}

	printf("%lld",mm);

	return 0;

}
// 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: 3.461667929074152x):
#include <bits/stdc++.h>

using namespace std;

int main()

{

	int n;

	scanf("%d",&n);

	int a[3][n];

	long long b[3][n];

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

	{

		for(int t=0;t<3;t++)

		{

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

		}

	}

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

	{

		b[i][0]=a[i][0];

	}

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

	{

		for(int t=0;t<3;t++)

		{

			b[t][i]=0;

		}

	}

	for(int i=1;i<n;i++)//从第二行开始遍历 

	{

		for(int t=0;t<3;t++)//遍历该行的每个状态 

		{

			for(int j=0;j<3;j++)//遍历上一行的每个状态 

			{

				if(j==t)continue;

				b[t][i]=max(b[t][i],b[j][i-1]+a[t][i]);

			}

		}

	}

	long long mm=b[0][n-1];

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

	{

		if(mm<b[i][n-1])mm=b[i][n-1];

	}

	printf("%lld",mm);

	return 0;

}
// 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: 2.249170836652944x):
#include <bits/stdc++.h>

using namespace std;

int main()

{

	int n;

	scanf("%d",&n);

	int a[3][n];

	long long b[3][n];

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

	{

		for(int t=0;t<3;t++)

		{

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

		}

	}

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

	{

		b[i][0]=a[i][0];

	}

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

	{

		for(int t=0;t<3;t++)

		{

			b[t][i]=0;

		}

	}

	for(int i=1;i<n;i++)//从第二行开始遍历 

	{

		for(int t=0;t<3;t++)//遍历该行的每个状态 

		{

			for(int j=0;j<3;j++)//遍历上一行的每个状态 

			{

				if(j==t)continue;

				b[t][i]=max(b[t][i],b[j][i-1]+a[t][i]);

			}

		}

	}

	long long mm=b[0][n-1];

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

	{

		if(mm<b[i][n-1])mm=b[i][n-1];

	}

	printf("%lld",mm);

	return 0;

}
// 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: 5.059895278145087x):
#include<iostream>

#include<cmath>

using namespace std;

int n,a[100005][3],dp[100005][3];

int main() 

{

   cin>>n;

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

    for(int h=0;h<3;h++)

      cin>>a[i][h];

   

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

   

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

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

  		if(h==0){

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

		  }

		else if(h==1){

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

		}

		else

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

		  

	  }

  }

   int ans=0;

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

     ans=max(ans,dp[n][i]);

     

    cout<<ans; 

   

	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: 3.3944166472040793x):
#include<iostream>

#include<cmath>

using namespace std;

int n,a[100005][3],dp[100005][3];

int main() 

{

   cin>>n;

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

    for(int h=0;h<3;h++)

      cin>>a[i][h];

   

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

   

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

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

  		if(h==0){

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

		  }

		else if(h==1){

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

		}

		else

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

		  

	  }

  }

   int ans=0;

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

     ans=max(ans,dp[n][i]);

     

    cout<<ans; 

   

	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: 1.7896748811551646x):
#include<iostream>

#include<cmath>

using namespace std;

int n,a[100005][3],dp[100005][3];

int main() 

{

   cin>>n;

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

    for(int h=0;h<3;h++)

      cin>>a[i][h];

   

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

   

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

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

  		if(h==0){

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

		  }

		else if(h==1){

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

		}

		else

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

		  

	  }

  }

   int ans=0;

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

     ans=max(ans,dp[n][i]);

     

    cout<<ans; 

   

	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: 2.209389339658417x):
#include<iostream>

#include<cmath>

using namespace std;

int n,a[100005][3],dp[100005][3];

int main() 

{

   cin>>n;

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

    for(int h=0;h<3;h++)

      cin>>a[i][h];

   

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

   

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

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

  		if(h==0){

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

		  }

		else if(h==1){

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

		}

		else

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

		  

	  }

  }

   int ans=0;

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

     ans=max(ans,dp[n][i]);

     

    cout<<ans; 

   

	return 0;

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

#include <string.h>

#define MAXN 100003



int array_a[MAXN][3];

int array_d[MAXN][3];



int max(int a,int b){

	return a>b? a:b;

}



int main(){

	memset(array_a,-1,sizeof(int)*MAXN*3);

	memset(array_d,-1,sizeof(int)*MAXN*3);

	int N;

	scanf("%d",&N);



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

		scanf("%d %d %d",&array_a[i][0],&array_a[i][1],&array_a[i][2]);

	}



	array_d[0][0]=array_a[0][0];

	array_d[0][1]=array_a[0][1];

	array_d[0][2]=array_a[0][2];

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

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

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

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

	}

	printf("%d",max(array_d[N-1][0],max(array_d[N-1][1],array_d[N-1][2])));

	return 0;



}

// Faster C++ solution for the same problem (measured speedup: 2.593124853256916x):
#include<iostream>

#include<cmath>

using namespace std;

int n,a[100005][3],dp[100005][3];

int main() 

{

   cin>>n;

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

    for(int h=0;h<3;h++)

      cin>>a[i][h];

   

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

   

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

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

  		if(h==0){

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

		  }

		else if(h==1){

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

		}

		else

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

		  

	  }

  }

   int ans=0;

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

     ans=max(ans,dp[n][i]);

     

    cout<<ans; 

   

	return 0;

}
// Slower C++ solution:
//       Author: Mostafa Mounir Shehab

 

#include <bits/stdc++.h>

using namespace std;

 

#define PI  3.14159265  // PI = acos(-1)

#define EPS (1e-10)

#define endl "\n"

#define SZ(v) (int)(v.size())

typedef long long ll;

typedef long double ld;

//template <class Type>

 

 

void Fast(){

	std::ios_base::sync_with_stdio(0);

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

}

 

inline int D(){

	int t;

	scanf("%d",&t);

	return t;

}

inline ll llD(){

	ll t;

	scanf("%lld",&t);

	return t;

}

 

 

ll MOD=1e9 + 7; 

const int N=1e5 + 5,M=50 + 1;

int arr[N][4];

ll dp[N][4];

ll OO=1e12; 

 

ll n,m,k,cnt,SU,idx,len,MN,MX;

ll l,r,mid;

ll a,b,c,d;



ll Solve(int idx,int row){

	

		

	if(idx == n)

		return 0;

	

	ll &ret = dp[idx][row];

	if(~ret)

		return ret;

	

	ret = -OO;

	

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

		if(row != i)

			ret = max(ret,arr[idx][i] + Solve(idx+1,i));

	

	return ret;

}







 

 

int main(){

	

	memset(dp, -1 ,sizeof dp);

	cin>>n;

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

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



	cout<<Solve(0,0)<<endl;

	



	





}

// Faster C++ solution for the same problem (measured speedup: 4.231426880643831x):
#include<iostream>

#include<cmath>

using namespace std;

int n,a[100005][3],dp[100005][3];

int main() 

{

   cin>>n;

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

    for(int h=0;h<3;h++)

      cin>>a[i][h];

   

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

   

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

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

  		if(h==0){

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

		  }

		else if(h==1){

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

		}

		else

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

		  

	  }

  }

   int ans=0;

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

     ans=max(ans,dp[n][i]);

     

    cout<<ans; 

   

	return 0;

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

#include <bits/stdc++.h>

#include <unordered_map>

#define stop(x) {cout<<x<<endl;exit(0);}

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

#define szz(s) int(s.size())

#define endl '\n'

int dx[] = { 0, 0, 1, -1, 1, -1, 1, -1 };

int dy[] = { 1, -1, 0, 0, -1, 1, 1, -1 };

typedef long long ll;

using namespace std;



void file() {

    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

#ifndef ONLINE_JUDGE

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

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

#endif

}





ll n;

ll mem[100004][4];

vector < vector < int > > v;



ll solve(int idx , int last) {

    if (idx == n)return 0;



    ll& ret = mem[idx][last];

    if (~ret)return ret;

    ret = 0;

    if (last != 0)ret = max(ret, solve(idx + 1, 0) + v[idx][0]);

    if (last != 1)ret = max(ret, solve(idx + 1, 1) + v[idx][1]);

    if (last != 2)ret = max(ret, solve(idx + 1, 2) + v[idx][2]);

    return ret;

}



int main() {

    //file();



    memset(mem, -1, sizeof mem);

    cin >> n;

    v = vector < vector < int > >(n, vector < int >(3));

    for (auto& e : v)

        for (auto& f : e)

            cin >> f;



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



}

// Faster C++ solution for the same problem (measured speedup: 4.240540262345327x):
#include<iostream>

#include<cmath>

using namespace std;

int n,a[100005][3],dp[100005][3];

int main() 

{

   cin>>n;

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

    for(int h=0;h<3;h++)

      cin>>a[i][h];

   

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

   

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

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

  		if(h==0){

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

		  }

		else if(h==1){

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

		}

		else

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

		  

	  }

  }

   int ans=0;

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

     ans=max(ans,dp[n][i]);

     

    cout<<ans; 

   

	return 0;

}
// Slower C++ solution:
/******

author :- Mahmoud Tarek.

*******/



#include<bits/stdc++.h>



using namespace std ;



#define rg register

#define dbg(v) cerr << #v << " " << v ;

typedef long long ll ;



int n;

struct doW{

int w[5] ;

};



vector<doW> a ;

int mem[100002][6] ;



int solve(int i, int ch){

if(i == n) return 0 ;

int & ret = mem[i][ch] ;

if(~ret) return ret ;

ret = 0 ;

for(int j = 2 ; j <= 4 ; j++){

    if(ch != j){

        ret = max(ret, a[i].w[j] + solve(i + 1, j)) ;

    }

}

return ret ;

}



int main() {

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

    cin >> n ;

    a.resize(n) ;

    memset(mem, -1, sizeof mem) ;

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

        for(int j = 2 ; j <= 4 ; j++) cin >> a[i].w[j] ;

    }

    cout << solve(0, 1) ;



}



/*

  Empty set of troubles.

*/


// Faster C++ solution for the same problem (measured speedup: 3.4066516590231593x):
#include<iostream>

#include<cmath>

using namespace std;

int n,a[100005][3],dp[100005][3];

int main() 

{

   cin>>n;

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

    for(int h=0;h<3;h++)

      cin>>a[i][h];

   

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

   

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

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

  		if(h==0){

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

		  }

		else if(h==1){

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

		}

		else

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

		  

	  }

  }

   int ans=0;

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

     ans=max(ans,dp[n][i]);

     

    cout<<ans; 

   

	return 0;

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

using namespace std;



const int N=1e5+30;

typedef long long ll;

int n;

int a[N],b[N],c[N];

ll dp[N][5];

ll solve(int i,int last){

    if(i==n)return 0;

    int path1=-1 ,path2=-1,path3=-1;

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

    if(~ret)return ret;

    if(last!=1){

        path1=a[i]+solve(i+1,1);

    }

    if(last!=2){

        path2=b[i]+solve(i+1,2);

    }

    if(last!=3){

        path3=c[i]+solve(i+1,3);

    }

    return ret=max(path1,max(path2,path3));



}

int main()

{

    memset(dp,-1,sizeof dp);

    cin>>n;

    for(int i=0;i<n;i++)cin>>a[i]>>b[i]>>c[i];

    cout<<solve(0,4);



}




// Faster C++ solution for the same problem (measured speedup: 5.083392004777523x):
#include<iostream>

#include<cmath>

using namespace std;

int n,a[100005][3],dp[100005][3];

int main() 

{

   cin>>n;

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

    for(int h=0;h<3;h++)

      cin>>a[i][h];

   

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

   

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

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

  		if(h==0){

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

		  }

		else if(h==1){

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

		}

		else

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

		  

	  }

  }

   int ans=0;

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

     ans=max(ans,dp[n][i]);

     

    cout<<ans; 

   

	return 0;

}
// Slower C++ solution:
/* MaTb3aa */

#include<bits/stdc++.h>

#define ll long long

using namespace std;

int n;

const int N = 100005;

vector<int>v;

ll dp[100005][4];

int A[N], B[N], C[N];

ll solve(int i,int lst) {

	if (i == n)return 0;

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

	if (~ret)return ret;

	if (lst != 1)ret = max(ret, solve(i + 1, 1) + A[i]);

	if (lst != 2)ret = max(ret, solve(i + 1, 2) + B[i]);

	if (lst != 3)ret = max(ret, solve(i + 1, 3) + C[i]);

	return ret;

}

int main() {

	cin >> n;

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

	memset(dp, -1, sizeof dp);

	cout << solve(0, 0);

	

		 

}

// Faster C++ solution for the same problem (measured speedup: 4.217523851115013x):
#include<iostream>

#include<cmath>

using namespace std;

int n,a[100005][3],dp[100005][3];

int main() 

{

   cin>>n;

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

    for(int h=0;h<3;h++)

      cin>>a[i][h];

   

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

   

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

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

  		if(h==0){

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

		  }

		else if(h==1){

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

		}

		else

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

		  

	  }

  }

   int ans=0;

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

     ans=max(ans,dp[n][i]);

     

    cout<<ans; 

   

	return 0;

}
// 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: 2.606986372239303x):
#include<iostream>

#include<cmath>

using namespace std;

int n,a[100005][3],dp[100005][3];

int main() 

{

   cin>>n;

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

    for(int h=0;h<3;h++)

      cin>>a[i][h];

   

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

   

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

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

  		if(h==0){

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

		  }

		else if(h==1){

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

		}

		else

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

		  

	  }

  }

   int ans=0;

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

     ans=max(ans,dp[n][i]);

     

    cout<<ans; 

   

	return 0;

}