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



using namespace std;

typedef long long ll;

typedef long long int lli;

typedef long double ld;

const int oo = 1e9;





int n;

const int nx = 1e5+5;

int ac[nx][3];

int dp[3][nx];

int go(int a, int i){

	if(i == n) return 0;

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

	int& ans = dp[a][i];

	

	if(a==0){

		ans=max(ans, go(1, i+1)+ac[i][0]);

		ans=max(ans, go(2, i+1)+ac[i][0]);

	}

	if(a==1){

		ans=max(ans, go(0, i+1)+ac[i][1]);

		ans=max(ans, go(2, i+1)+ac[i][1]);

	}

	if(a==2){

		ans=max(ans, go(0, i+1)+ac[i][2]);

		ans=max(ans, go(1, i+1)+ac[i][2]);

	}

	

	return ans;

}

int main(){

	cin>>n;

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

	memset(dp, -1, sizeof dp);

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

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 2.235510671345534x):
#include<bits/stdc++.h>



#define SORT(v) sort(v.begin(),v.end())

#define si(n) scanf("%d",&n)

#define sii(n,m) scanf("%d %d",&n,&m)

#define sl(n) scanf("%lld",&n)

#define sll(n,m) scanf("%lld %lld",&n,&m)

#define ss(cad) scanf("%s",cad)

#define fst first

#define scn second

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

#define M 1000000007

#define N_MAX 100010



using namespace std;



typedef long long ll;

typedef vector<int> vi;

typedef vector<bool> vb;

typedef vector<ll> vl;

typedef pair<int,int> pi;

typedef pair<ll, ll> pll;

typedef vector<pi> vp;



ll costo[100100][3];

ll dp[100100][3];



int main(){

	int n;

	si(n);

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

		sl(costo[i][0]);

		sl(costo[i][1]);

		sl(costo[i][2]);

	}	

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

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

			dp[i][j] = 0;

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

				if(j == k)

					continue;

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

			}

		}

	}

	ll ans = max(dp[n][0], dp[n][1]);

	ans = max(ans, dp[n][2]);

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

    return 0;

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

using namespace std;

typedef long long ll;

typedef long long int lli;

typedef long double ld;

const int oo = 1e9; 



int m;

const int mx = 1e5+5;

int ac[mx][3];

int dp[3][mx];

int go(int a, int i){

	if(i == m) return 0;

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

	int& ans = dp[a][i];

	

	if(a==0){

		ans=max(ans, go(1, i+1)+ac[i][0]);

		ans=max(ans, go(2, i+1)+ac[i][0]);

	}

	if(a==1){

		ans=max(ans, go(0, i+1)+ac[i][1]);

		ans=max(ans, go(2, i+1)+ac[i][1]);

	}

	if(a==2){

		ans=max(ans, go(0, i+1)+ac[i][2]);

		ans=max(ans, go(1, i+1)+ac[i][2]);

	}

	

	return ans;

}

int main(){

	cin>>m;

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

	memset(dp, -1, sizeof dp);

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

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 2.2355332449169167x):
#include<bits/stdc++.h>



#define SORT(v) sort(v.begin(),v.end())

#define si(n) scanf("%d",&n)

#define sii(n,m) scanf("%d %d",&n,&m)

#define sl(n) scanf("%lld",&n)

#define sll(n,m) scanf("%lld %lld",&n,&m)

#define ss(cad) scanf("%s",cad)

#define fst first

#define scn second

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

#define M 1000000007

#define N_MAX 100010



using namespace std;



typedef long long ll;

typedef vector<int> vi;

typedef vector<bool> vb;

typedef vector<ll> vl;

typedef pair<int,int> pi;

typedef pair<ll, ll> pll;

typedef vector<pi> vp;



ll costo[100100][3];

ll dp[100100][3];



int main(){

	int n;

	si(n);

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

		sl(costo[i][0]);

		sl(costo[i][1]);

		sl(costo[i][2]);

	}	

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

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

			dp[i][j] = 0;

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

				if(j == k)

					continue;

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

			}

		}

	}

	ll ans = max(dp[n][0], dp[n][1]);

	ans = max(ans, dp[n][2]);

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

    return 0;

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

using namespace std;

typedef long long ll;

typedef long long int lli;

typedef long double ld;

const int oo = 1e9;



int n;

const int nx = 1e5+5;

int ac[nx][3];

int dp[3][nx];

int go(int a, int i)

{

	if(i==n) return 0;

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

	int& ans = dp[a][i];

	if(a==0)

	{

		ans=max(ans, go(1, i+1)+ac[i][0]);

		ans=max(ans, go(2, i+1)+ac[i][0]);

	}

	if(a==1)

	{

		ans=max(ans, go(0, i+1)+ac[i][1]);

		ans=max(ans, go(2, i+1)+ac[i][1]);

	}

	if(a==2)

	{

		ans=max(ans, go(0, i+1)+ac[i][2]);

		ans=max(ans, go(1, i+1)+ac[i][2]);

	}

	

	return ans;

	

}

int main()

{

    cin>>n;

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

    memset(dp, -1, sizeof dp);

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

}

	

// Faster C++ solution for the same problem (measured speedup: 2.235510671345534x):
#include<bits/stdc++.h>



#define SORT(v) sort(v.begin(),v.end())

#define si(n) scanf("%d",&n)

#define sii(n,m) scanf("%d %d",&n,&m)

#define sl(n) scanf("%lld",&n)

#define sll(n,m) scanf("%lld %lld",&n,&m)

#define ss(cad) scanf("%s",cad)

#define fst first

#define scn second

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

#define M 1000000007

#define N_MAX 100010



using namespace std;



typedef long long ll;

typedef vector<int> vi;

typedef vector<bool> vb;

typedef vector<ll> vl;

typedef pair<int,int> pi;

typedef pair<ll, ll> pll;

typedef vector<pi> vp;



ll costo[100100][3];

ll dp[100100][3];



int main(){

	int n;

	si(n);

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

		sl(costo[i][0]);

		sl(costo[i][1]);

		sl(costo[i][2]);

	}	

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

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

			dp[i][j] = 0;

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

				if(j == k)

					continue;

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

			}

		}

	}

	ll ans = max(dp[n][0], dp[n][1]);

	ans = max(ans, dp[n][2]);

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

    return 0;

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

using namespace std;

const int mx=100010;

int arr[mx][3],n;

int dp[mx][3];

int f(int pos,int ty){

	if(pos==n)return 0;

	int &ans=dp[pos][ty];

	if(ans^-1)return ans;

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

		if(ty^i || !pos){

			ans=max(ans,f(pos+1,i)+arr[pos][i]);

		}

	}

	return ans;

}



int main(int argc, char const *argv[])

{

	memset(dp,-1,sizeof dp);

	cin>>n;

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

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

			cin>>arr[i][j];

		}

	}

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



	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 2.236948566464287x):
#include<bits/stdc++.h>



#define SORT(v) sort(v.begin(),v.end())

#define si(n) scanf("%d",&n)

#define sii(n,m) scanf("%d %d",&n,&m)

#define sl(n) scanf("%lld",&n)

#define sll(n,m) scanf("%lld %lld",&n,&m)

#define ss(cad) scanf("%s",cad)

#define fst first

#define scn second

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

#define M 1000000007

#define N_MAX 100010



using namespace std;



typedef long long ll;

typedef vector<int> vi;

typedef vector<bool> vb;

typedef vector<ll> vl;

typedef pair<int,int> pi;

typedef pair<ll, ll> pll;

typedef vector<pi> vp;



ll costo[100100][3];

ll dp[100100][3];



int main(){

	int n;

	si(n);

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

		sl(costo[i][0]);

		sl(costo[i][1]);

		sl(costo[i][2]);

	}	

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

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

			dp[i][j] = 0;

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

				if(j == k)

					continue;

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

			}

		}

	}

	ll ans = max(dp[n][0], dp[n][1]);

	ans = max(ans, dp[n][2]);

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

    return 0;

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

#include<cstring>

using namespace std;



#define Max 100001

int dp[Max][3];



int main(){

	int n,a,b,c;

	memset(dp,0,sizeof(dp));

	cin>>n;

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

		cin>>a>>b>>c;

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

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

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

	}

	int ans=max(max(dp[n][0],dp[n][1]),dp[n][2]);

	cout<<ans<<endl;

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 2.236306516947282x):
#include<bits/stdc++.h>



#define SORT(v) sort(v.begin(),v.end())

#define si(n) scanf("%d",&n)

#define sii(n,m) scanf("%d %d",&n,&m)

#define sl(n) scanf("%lld",&n)

#define sll(n,m) scanf("%lld %lld",&n,&m)

#define ss(cad) scanf("%s",cad)

#define fst first

#define scn second

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

#define M 1000000007

#define N_MAX 100010



using namespace std;



typedef long long ll;

typedef vector<int> vi;

typedef vector<bool> vb;

typedef vector<ll> vl;

typedef pair<int,int> pi;

typedef pair<ll, ll> pll;

typedef vector<pi> vp;



ll costo[100100][3];

ll dp[100100][3];



int main(){

	int n;

	si(n);

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

		sl(costo[i][0]);

		sl(costo[i][1]);

		sl(costo[i][2]);

	}	

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

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

			dp[i][j] = 0;

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

				if(j == k)

					continue;

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

			}

		}

	}

	ll ans = max(dp[n][0], dp[n][1]);

	ans = max(ans, dp[n][2]);

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

    return 0;

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

using namespace std ;

#define ll long long

inline int D(){

    int t ;

    scanf( "%d" , &t ) ;

    return t ;

}

inline ll LLD(){

    ll t ;

    scanf( "%lld" , &t ) ;

    return t ;

}

//################################################################

const int N=100009;

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

int mem[N][4];

int solve(int ind ,int lastInd){

    if(ind==n)return 0;

    int  ret=INT_MIN;

    if(mem[ind][lastInd]!=-1)return mem[ind][lastInd];

    if(lastInd!=0){



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

    }

    if(lastInd!=1){



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

    }

    if(lastInd!=2){



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

    }

    return mem[ind][lastInd]=ret;



}

int main() {

    n=D();

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

        a[i]=D(),b[i]=D(),c[i]=D();

    }

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

    printf("%d",solve(0,3));





}

// Faster C++ solution for the same problem (measured speedup: 2.620339732808484x):
#include<bits/stdc++.h>



#define SORT(v) sort(v.begin(),v.end())

#define si(n) scanf("%d",&n)

#define sii(n,m) scanf("%d %d",&n,&m)

#define sl(n) scanf("%lld",&n)

#define sll(n,m) scanf("%lld %lld",&n,&m)

#define ss(cad) scanf("%s",cad)

#define fst first

#define scn second

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

#define M 1000000007

#define N_MAX 100010



using namespace std;



typedef long long ll;

typedef vector<int> vi;

typedef vector<bool> vb;

typedef vector<ll> vl;

typedef pair<int,int> pi;

typedef pair<ll, ll> pll;

typedef vector<pi> vp;



ll costo[100100][3];

ll dp[100100][3];



int main(){

	int n;

	si(n);

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

		sl(costo[i][0]);

		sl(costo[i][1]);

		sl(costo[i][2]);

	}	

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

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

			dp[i][j] = 0;

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

				if(j == k)

					continue;

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

			}

		}

	}

	ll ans = max(dp[n][0], dp[n][1]);

	ans = max(ans, dp[n][2]);

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

    return 0;

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

using namespace std;

typedef long long ll;

typedef unsigned long long ull;

const int N = 1e5+10 , OO = 0x3f3f3f3f ;

//const int mod = 1000000007;

 

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

double startTime;

double getCurrentTime() {

	return ((double)clock() - startTime) / CLOCKS_PER_SEC;

}

#define clr(arr,val) memset(arr , val , sizeof (arr))

#define loop(i,n) for(int i = 0;i < int(n);i++)

#define rloop(i,n) for(int i = int(n)-1;i >= 0;i--)

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

#define range(vec) for(auto &x : vec) cin >> x;

#define ALL(v) ((v).begin()) , ((v).end())

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

int dx[]={1,0,-1,0};int dy[]={0,1,0,-1}; //4 Direction

//int dx[]={1,1,0,-1,-1,-1,0,1};int dy[]={0,1,1,1,0,-1,-1,-1};//8 direction

//int dx[]={2,1,-1,-2,-2,-1,1,2};int dy[]={1,2,2,1,-1,-2,-2,-1};//Knight Direction

//int dx[6]={2,1,-1,-2,-1,1};int dy[6]={0,1,1,0,-1,-1}; //Hexagonal Direction

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

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



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

int dp[N][4];



int solve(int idx , int lst){

	

	if(idx == n) return 0;

	int& ret = dp[idx][lst];

	if(~ret) return ret;

	ret = -OO;

	if(lst != 0) // swim

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

	if(lst != 1)

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

	if(lst != 2)

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

		

	return ret;

}





int main()

{

    startTime = (double)clock();

    #ifndef ONLINE_JUDGE

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

        //freopen("out.in", "w", stdout);

    #endif

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

	

	cin >> n;

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

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



	clr(dp , -1);

	cout << solve(0 , 3) << "\n";





    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 2.6612307061352265x):
#include<bits/stdc++.h>



#define SORT(v) sort(v.begin(),v.end())

#define si(n) scanf("%d",&n)

#define sii(n,m) scanf("%d %d",&n,&m)

#define sl(n) scanf("%lld",&n)

#define sll(n,m) scanf("%lld %lld",&n,&m)

#define ss(cad) scanf("%s",cad)

#define fst first

#define scn second

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

#define M 1000000007

#define N_MAX 100010



using namespace std;



typedef long long ll;

typedef vector<int> vi;

typedef vector<bool> vb;

typedef vector<ll> vl;

typedef pair<int,int> pi;

typedef pair<ll, ll> pll;

typedef vector<pi> vp;



ll costo[100100][3];

ll dp[100100][3];



int main(){

	int n;

	si(n);

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

		sl(costo[i][0]);

		sl(costo[i][1]);

		sl(costo[i][2]);

	}	

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

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

			dp[i][j] = 0;

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

				if(j == k)

					continue;

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

			}

		}

	}

	ll ans = max(dp[n][0], dp[n][1]);

	ans = max(ans, dp[n][2]);

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

    return 0;

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

#define F first

#define S second

#define T second.first

#define C second.second

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

using namespace std;

typedef long long ll;

typedef pair<int, int> pii;

typedef pair<int,pair<int,int>> piii;



const int N= 1e5+5, L = 14, OO = 0x3f3f3f3f;

const ll M=10 ;

const double ESP = 1e-8;



int n, k;

piii A[N];

int dp[N][5];

int solve(int idx, int prev){

    if(idx == n)

        return 0;



    int& ret = dp[idx][prev];

    if(~ret)

        return ret;



    ret = max(ret, (prev != 1)? solve(idx+1, 1)+A[idx].F : -1);

    ret = max(ret, (prev != 2)? solve(idx+1, 2)+A[idx].T : -1);

    return ret = max(ret, (prev != 3)? solve(idx+1, 3)+A[idx].C : -1);



}



int main(){

    FIO

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

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

    cin>>n;

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

    memset(dp, -1, sizeof dp);

    cout<<solve(0,4);

}


// Faster C++ solution for the same problem (measured speedup: 3.053868643650021x):
#include<bits/stdc++.h>



#define SORT(v) sort(v.begin(),v.end())

#define si(n) scanf("%d",&n)

#define sii(n,m) scanf("%d %d",&n,&m)

#define sl(n) scanf("%lld",&n)

#define sll(n,m) scanf("%lld %lld",&n,&m)

#define ss(cad) scanf("%s",cad)

#define fst first

#define scn second

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

#define M 1000000007

#define N_MAX 100010



using namespace std;



typedef long long ll;

typedef vector<int> vi;

typedef vector<bool> vb;

typedef vector<ll> vl;

typedef pair<int,int> pi;

typedef pair<ll, ll> pll;

typedef vector<pi> vp;



ll costo[100100][3];

ll dp[100100][3];



int main(){

	int n;

	si(n);

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

		sl(costo[i][0]);

		sl(costo[i][1]);

		sl(costo[i][2]);

	}	

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

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

			dp[i][j] = 0;

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

				if(j == k)

					continue;

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

			}

		}

	}

	ll ans = max(dp[n][0], dp[n][1]);

	ans = max(ans, dp[n][2]);

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

    return 0;

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



using namespace std;



const int N=1e5;

int n;

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

int mem[N][5];



int solve(int i,int lst){

    if(i==n)

        return 0;

    if(mem[i][lst]!=-1) return mem[i][lst];

    int op1=lst!=0?solve(i+1,0)+a[i]:-1000000000;

    int op2=lst!=1?solve(i+1,1)+b[i]:-1000000000;

    int op3=lst!=2?solve(i+1,2)+c[i]:-1000000000;

    return mem[i][lst]=max(op1,max(op2,op3));

}



int main() {

    scanf("%d",&n);

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

        scanf("%d%d%d",a+i,b+i,c+i);

    memset(mem,-1,sizeof mem);

    printf("%d",max(solve(0,0),max(solve(0,1),solve(0,2))));

    return 0;

}


// Faster C++ solution for the same problem (measured speedup: 3.031410981992153x):
#include<bits/stdc++.h>



#define SORT(v) sort(v.begin(),v.end())

#define si(n) scanf("%d",&n)

#define sii(n,m) scanf("%d %d",&n,&m)

#define sl(n) scanf("%lld",&n)

#define sll(n,m) scanf("%lld %lld",&n,&m)

#define ss(cad) scanf("%s",cad)

#define fst first

#define scn second

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

#define M 1000000007

#define N_MAX 100010



using namespace std;



typedef long long ll;

typedef vector<int> vi;

typedef vector<bool> vb;

typedef vector<ll> vl;

typedef pair<int,int> pi;

typedef pair<ll, ll> pll;

typedef vector<pi> vp;



ll costo[100100][3];

ll dp[100100][3];



int main(){

	int n;

	si(n);

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

		sl(costo[i][0]);

		sl(costo[i][1]);

		sl(costo[i][2]);

	}	

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

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

			dp[i][j] = 0;

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

				if(j == k)

					continue;

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

			}

		}

	}

	ll ans = max(dp[n][0], dp[n][1]);

	ans = max(ans, dp[n][2]);

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

    return 0;

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

using namespace std;

#define ll long long

#define ull unsigned long long

#define PII pair<int,int>

#define PSI pair<string,int>

#define PIII pair< int, pair<int,int> >

const int MXN = 1e5+5;

int a[MXN][4], dp[MXN][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 read(){



    int i,j;

    cin>>N;

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

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

            cin>>a[i][j];

}



void solve(){



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

    read();

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

}



int main(){



    ios_base::sync_with_stdio(false);

    cin.tie(nullptr);

    solve();

}


// Faster C++ solution for the same problem (measured speedup: 2.6492549763870072x):
#include<bits/stdc++.h>



#define SORT(v) sort(v.begin(),v.end())

#define si(n) scanf("%d",&n)

#define sii(n,m) scanf("%d %d",&n,&m)

#define sl(n) scanf("%lld",&n)

#define sll(n,m) scanf("%lld %lld",&n,&m)

#define ss(cad) scanf("%s",cad)

#define fst first

#define scn second

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

#define M 1000000007

#define N_MAX 100010



using namespace std;



typedef long long ll;

typedef vector<int> vi;

typedef vector<bool> vb;

typedef vector<ll> vl;

typedef pair<int,int> pi;

typedef pair<ll, ll> pll;

typedef vector<pi> vp;



ll costo[100100][3];

ll dp[100100][3];



int main(){

	int n;

	si(n);

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

		sl(costo[i][0]);

		sl(costo[i][1]);

		sl(costo[i][2]);

	}	

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

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

			dp[i][j] = 0;

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

				if(j == k)

					continue;

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

			}

		}

	}

	ll ans = max(dp[n][0], dp[n][1]);

	ans = max(ans, dp[n][2]);

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

    return 0;

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

using namespace std;

typedef long long int ll;

const int MAX=1e5+10;

int N,A[MAX],B[MAX],C[MAX],dp[MAX][3];

int solve(int idx,int pr)

{

    if(idx>N)return 0;

    if(dp[idx][pr]!=-1)return dp[idx][pr];

    int res=0;

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

        if(i==pr)continue;

        int val=0;

        if(i==1)val=A[idx];

        if(i==2)val=B[idx];

        if(i==3)val=C[idx];

        res = max(res,solve(idx+1,i)+val);

    }

    return dp[idx][pr]=res;

}

int  main ()

{

    memset(dp,-1,sizeof dp);

    cin >> N;

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

        cin >> A[i] >> B[i] >> C[i];

    }

    cout<<solve(1,0)<<endl;

    return 0;

}






// Faster C++ solution for the same problem (measured speedup: 2.1824738499428777x):
#include <bits/stdc++.h>

using namespace std;



int main() {

    ios_base::sync_with_stdio(false); cin.tie(NULL);

    int n;

    cin >> n;

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

    long long dp[n][3];

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

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

    }

    dp[0][0] = a[0];

    dp[0][1] = b[0];

    dp[0][2] = c[0];

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

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

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

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

    }

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

    return 0;

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

using namespace std;

#define print printf("==================\n")

#define ll long long

#define pi acos(-1.0)

#define eps 1e-16

#define max3(a,b,c) max(a,max(b,c))

const ll INF = 1 << 30;

typedef pair<ll, ll  > payar;

typedef struct

{

    ll  x, y;

} point;

priority_queue<payar, vector<payar>,  greater<payar> > pq; ///accending

vector< pair<ll,payar  > > vpp;

vector < payar >  vp;



ll n ;

int ara[100005][4];

ll dp[100005][4];

ll cal(int day, int itm)

{

    if(day>n)

    {

        return 0;

    }



    if(dp[day][itm]!=-1)

        return dp[day][itm];

    ll maxi = -1;

    if(day==1)

    {

   return   maxi = dp[day][itm]=max3( cal(day+1,1)+ara[day][1], cal(day+1,2)+ara[day][2], cal(day+1,3)+ara[day][3] );



    }

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

    {

            if(i==itm)

                continue;

            maxi=max( cal(day+1,i)+ara[day][i],maxi);





    }

    return dp[day][itm]=maxi;

}



int main()

{



    cin>>n;

    memset(dp,-1,sizeof dp);

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

    {

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

        {

            cin>>ara[i][j];

        }

    }

    cout<<cal(1,1);







    return  0 ;

}


// Faster C++ solution for the same problem (measured speedup: 4.16789825515127x):
#include <bits/stdc++.h>

using namespace std;



int main() {

    ios_base::sync_with_stdio(false); cin.tie(NULL);

    int n;

    cin >> n;

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

    long long dp[n][3];

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

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

    }

    dp[0][0] = a[0];

    dp[0][1] = b[0];

    dp[0][2] = c[0];

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

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

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

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

    }

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

    return 0;

}