Problem:
Score : 100 points

Problem Statement

Taro's summer vacation starts tomorrow, and he has decided to make plans for it now.

The vacation consists of N days.
For each i (1 \leq i \leq N), Taro will choose one of the following activities and do it on the i-th day:

A: Swim in the sea. Gain a_i points of happiness.

B: Catch bugs in the mountains. Gain b_i points of happiness.

C: Do homework at home. Gain c_i points of happiness.

As Taro gets bored easily, he cannot do the same activities for two or more consecutive days.

Find the maximum possible total points of happiness that Taro gains.

Constraints

All values in input are integers.

1 \leq N \leq 10^5

1 \leq a_i, b_i, c_i \leq 10^4

Input

Input is given from Standard Input in the following format:

N
a_1 b_1 c_1
a_2 b_2 c_2
:
a_N b_N c_N

Output

Print the maximum possible total points of happiness that Taro gains.

Sample Input 1

3
10 40 70
20 50 80
30 60 90

Sample Output 1

210

If Taro does activities in the order C, B, C, he will gain 70 + 50 + 90 = 210 points of happiness.

Sample Input 2

1
100 10 1

Sample Output 2

100

Sample Input 3

7
6 7 8
8 8 3
2 5 2
7 8 6
4 6 8
2 3 4
7 5 1

Sample Output 3

46

Taro should do activities in the order C, A, B, A, C, B, A.

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

/* package codechef; // don't place package name! */
import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
public class Main
{
	public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
		FastReader sc=new FastReader();
// 		constructST(a,n);RMQ(n, qs, qe)
        // sieveOfEratosthenes();
		int n = sc.nextInt();
		long dp1[] = new long[n], dp2[] = new long[n], dp3[] = new long[n];
		Arrays.fill(dp1, 0);
		Arrays.fill(dp2, 0);
		Arrays.fill(dp3, 0);
		
		for(int i = 0; i < n; i++) {
			long a = sc.nextLong(), b = sc.nextLong(), c = sc.nextLong();
			if(i == 0) {
				dp1[0] = a; 
				dp2[0] = b;
				dp3[0] = c;
			}else {
				dp1[i] = Math.max(dp1[i - 1], a + Math.max(dp2[i - 1], dp3[i - 1]));
				dp2[i] = Math.max(dp2[i - 1], b + Math.max(dp1[i - 1], dp3[i - 1]));
				dp3[i] = Math.max(dp3[i - 1], c + Math.max(dp2[i - 1], dp1[i - 1]));
			}
		}
		System.out.println(Math.max(dp1[n - 1], Math.max(dp2[n - 1], dp3[n - 1])));
	}
    static int lower_bound(ArrayList <Long> ar,long x){
	    int n=ar.size(),low=0,high=n-1,res=-1;
	    while(low<=high){
	    	int mid=(low+high)>>1;
         
	    	if(ar.get(mid) >= x){
	    		res=mid;
	    		high = mid - 1;
	    	}
	    	else 
	    		low = mid + 1;
	    }
	    return res;
	}
    static int upper_bound(int a[],int x){
         int n=a.length,low=0,high=n-1,res=-1;
         while(low<=high){
             int mid=(low+high)>>1;
             if(a[mid]<=x){
                 res=mid;
                 low = mid + 1;
             }
             else 
                 high = mid - 1;
         }
         return res;
     }
    //   static int MAX=1000001;boolean prime[] = new boolean[MAX]; 
      
    //   static void sieveOfEratosthenes() { 
    //       for(int m9=0;m9<MAX;m9++) prime[m9]=true;
    //     for(int p = 2; p*p <=n; p++) { 
    //         if(prime[p] == true) 
    //         { 
    //             // Update all multiples of p 
    //             for(int i = p*2; i <= n; i += p) 
    //                 prime[i] = false; 
    //         } 
    //     } 
    //   }
      
      static long modexpo(long x,long n,long m){
        if(n==0)
            return 1;
        else if(n%2==0)
            return (modexpo(((x%m)*(x%m))%m,n/2,m))%m;
        else
            return ((x%m)*((modexpo(((x%m)*(x%m))%m,(n-1)/2,m))%m))%m;
      } 
       static int gcd(int a,int b){
           if(b==0)
              return a;
           else 
              return gcd(b,a%b);
       }
       static long gcd(long a,long b){
           if(b==0)
              return a;
           else 
              return gcd(b,a%b);
       }
	 static class FastReader{
          BufferedReader in;
          StringTokenizer st;
          public FastReader(){
              in=new BufferedReader(new InputStreamReader(System.in));
          }
          String next(){
              while(st==null || !st.hasMoreElements()){
                  try{
                      st=new StringTokenizer(in.readLine());
                  }
                  catch(IOException e){
                      e.printStackTrace();
                  }
               }
               return st.nextToken();
            }
            int nextInt(){
                return Integer.parseInt(next());
            }
            long nextLong(){
                return Long.parseLong(next());
            }
            double nextDouble(){
                return Double.parseDouble(next());
            }
            String nextLine(){
            String str19 = "";
            try{
                str19 = in.readLine();
            }
            catch (IOException e){ 
                e.printStackTrace();
             }
            return str19;
        }
      }    
}