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 JavaScript (node.js v5.12) (judge verdict: Accepted)

var obj = init();
Main();
function nextInt(){return myconv(next(),1);}
function nextStrArray(){return myconv(next(),2);}//半角スペース分割
function nextIntArray(){return myconv(next(),4);}//半角スペース + 数値化
function nextCharArray(){return myconv(next(),6);}//1文字分割
function next(){return obj.next();}
function hasNext(){return obj.hasNext();}
function myin(){return require("fs").readFileSync("/dev/stdin", "utf8").trim().split("\n");}
function init(){
  var inputFile = myin();
  var returnObj = {
    "list" : inputFile, "index" : 0, "max" : inputFile.length,
    "hasNext" : function(){return (this.index < this.max);},
    "next" : function(){if(!this.hasNext()){return "";}else{var returnInput = this.list[this.index];this.index++;return returnInput;}}
  };
  return returnObj;
}
function myout(t){console.log(t);}//標準出力
function myerr(t){console.error(t);}//標準エラー出力
//[no]要素の扱い。数値型
//不明値、異常時:引数そのまま返す　1:数値へ変換
//2:半角SPで分割 4:半角SPで分割し、数値配列へ
//6:1文字で分割  7:1文字で分割し、数値配列へ
//8:半角SPで結合 9:改行で結合 0:文字なしで結合
function myconv(i,no){try{switch(no){case 1:return parseInt(i);case 2:return i.split(" ");case 4:return i.split(" ").map((a)=>Number(a));case 6:return i.split("");case 7:return i.split("").map((a)=>Number(a));case 8:return i.join(" ");case 9:return i.join("\n");case 0:return i.join("");default:return i;}}catch(e){return i;}}
function Main(){
  var N = nextInt();
  var used;
  var dp = new Array(N + 1);
  var list = new Array(N);
  dp[0] = new Array(3).fill(0);
  for(var i = 1; i <= N; i++){
    dp[i] = new Array(3);
    list[i - 1] = nextIntArray();
  }
  for(var i = 0; i < N; i++){
    dp[i + 1][0] = Math.max(dp[i][1],dp[i][2]) + list[i][0];
    dp[i + 1][1] = Math.max(dp[i][0],dp[i][2]) + list[i][1];
    dp[i + 1][2] = Math.max(dp[i][0],dp[i][1]) + list[i][2];
  }
  myout(Math.max.apply(null,dp[N]));
}