import java.io.*;
import java.util.*;
import java.math.BigInteger;

public class Main {


	public void readInput() throws Exception {
 		  
 			 
 		//BufferedReader buf = new BufferedReader(new InputStreamReader(System.in));
 		//BufferedReader buf = new BufferedReader(new FileReader("input.txt"));         
        int N = input.nextInt();
        int [][] tasks = new int[N][3];
        int [][] dp = new int[N][3];
        for(int i=0;i<N;i++){
            tasks[i][0] = input.nextInt();
            tasks[i][1] = input.nextInt();
            tasks[i][2] = input.nextInt();
        }
        dp[0][0] = tasks[0][0];
        dp[0][1] = tasks[0][1];
        dp[0][2] = tasks[0][2];
        int max = 0;
        for(int i=1;i<N;i++){
            for(int j=0;j<3;j++){
                max = 0;
                for(int k=0;k<3;k++){
                    if(k!=j) {
                        max = Math.max(dp[i-1][k], max);
                        //System.out.printf("tasks[%d][%d]: %d max: %d\n",(i-1), k, tasks[i-1][k], max);
                    }
                }
                //System.out.printf("max: %d\n",max);
                dp[i][j] = tasks[i][j] + max ;
                //System.out.printf("dp[%d][%d]: %d\n",i,j, dp[i][j]);
            }
        }
        max =0;
        for(int i=0;i<3;i++){
            max = Math.max(max, dp[N-1][i]);
        }
        System.out.printf("%d\n",max);
           
    }

    private void print(int[][] matrix) {
        for(int i=0;i<matrix.length;i++){
            System.out.println(Arrays.toString(matrix[i]));
        }
        System.out.println();
    }
  
   

    private static void swap(char []array, int i, int j){
        char temp = array[i];
        array[i] = array[j];
        array[j] = temp;
    }
 

	public static void main(String[] args) throws Exception {
		Main ans = new Main();
		ans.readInput(); 
        out.close();
		//shouldReturn10();
		
	}


    private static InputStream inputStream = System.in;
    private static InputReader input = new InputReader(inputStream);
    private static OutputStream outputStream = System.out;
    private static PrintWriter out = new PrintWriter(outputStream);
	 
    static class InputReader {
        private BufferedReader buf;
        private StringTokenizer token;
        public InputReader(InputStream inputStream){
            buf = new BufferedReader(new InputStreamReader(inputStream),32768);
            token = null;
        }
        
        private String next(){
            while(token==null || !token.hasMoreTokens()){
                try{
                    token = new StringTokenizer(buf.readLine());
                }catch(Exception e){
                    throw new RuntimeException("Error in reading input",e);
                }
            }
            return token.nextToken();
        }
        
        public int nextInt(){
            return Integer.parseInt(next());
        }

        public String nextString(){
            return next();
        }

        public long nextLong(){
            return Long.parseLong(next());
        }
    }
}

class XCoordinateComparator implements Comparator<Point>{

    public int compare(Point p1, Point p2){
        if (p1.x == p2.x) return p1.y - p2.y;
        return p1.x-p2.x;
    }

}
class YCoordinateComparator implements Comparator<Point>{

    public int compare(Point p1, Point p2){
        if (p1.y == p2.y) return p1.x - p2.x;
        return p1.y-p2.y;
    }

}
class Point{
    int x,y;
    public Point(int x, int y){
        this.x = x;
        this.y = y;
    }
    public String toString(){
        return "("+x+","+y+")";
    }

    public int hashCode(){
        String s = x+""+y;
        return s.hashCode();
    }
    @Override
    public boolean equals(Object obj){
        Point p = (Point) obj;         
        return this.x == p.x && this.y == p.y;
    }
}
class DNode{
    int val;
    int index;
    DNode next,prev;
    public DNode(int val, int index){
        this.val = val;
        this.index = index;
    }
    public boolean equals(Object o){
        if (!(o instanceof DNode)){
            return false;
        }
        DNode other = (DNode)o;
        return (other.val==this.val) && (other.index == this.index);

    }

    public String toString() {
        return this.index + " -> " + this.val;
    }
}
class DList{

    DNode tail,head;
    int count;

    public DList() {
        tail = new DNode(-1,-1);         
        head = new DNode(-2,-2);
        head.next = tail;
        head.prev = tail;
        tail.prev = head;
        tail.next = head;
        count =0;
    }
    public void add(int val, int index){
        DNode curr = new DNode(val, index);
        count++;
        addNode(curr);
    }
    public void addLast(int val, int index){
        DNode curr = new DNode(val, index);
        count++;
        addLast(curr);
    }

    private void addNode(DNode curr) {
        DNode temp = head.next;
        head.next = curr;
        curr.prev = head;

        curr.next = temp;
        temp.prev = curr;
    }

    private void addLast(DNode curr) {
        DNode temp = tail.prev;
        tail.prev = curr;
        curr.next = tail;

        curr.prev = temp;
        temp.next = curr;
    }

    public boolean hasNext(){
        return !head.next.equals(tail);
    }
    public DNode remove() {
        count--;
        DNode temp = head.next;
        DNode nextNode = temp.next;
        head.next = nextNode;
        nextNode.prev = head;
        return temp;
    }
    
    public int size(){
        return count;
    }

    public void printNodes() {
        DNode curr = head.next;
        while(!curr.equals(tail)){
            System.out.println(curr);
            //System.out.print("->");
            curr = curr.next;
        }
        System.out.println("NULL");
    }


}

Measured memory_bytes: 52744