import java.io.*;
import java.util.*;

public class Main {

    public static void main(String[] args) throws Exception {
        pw = new PrintWriter(System.out);
        sc = new MScanner(System.in);
        int n = sc.nextInt();
        int[] a = new int[n + 1], b = new int[n + 1], c = new int[n + 1];
        for(int i = 1; i <= n; ++i){
            a[i] = sc.nextInt();
            b[i] = sc.nextInt();
            c[i] = sc.nextInt();
        }
        int[][] dp = new int[n + 1][3];
        for(int day = 1; day <= n; ++day){
            dp[day][0] = a[day] + Math.max(dp[day - 1][1], dp[day - 1][2]);
            dp[day][1] = b[day] + Math.max(dp[day - 1][0], dp[day - 1][2]);
            dp[day][2] = c[day] + Math.max(dp[day - 1][1], dp[day - 1][0]);
        }
        pw.println(Math.max(Math.max(dp[n][0], dp[n][1]), dp[n][2]));
        pw.flush();
    }
    static PrintWriter pw;
    static MScanner  sc;
    static class MScanner {
        StringTokenizer st;
        BufferedReader br;
        public MScanner(InputStream system) {
            br = new BufferedReader(new InputStreamReader(system));
        }

        public MScanner(String file) throws Exception {
            br = new BufferedReader(new FileReader(file));
        }

        public String next() throws IOException {
            while (st == null || !st.hasMoreTokens())
                st = new StringTokenizer(br.readLine());
            return st.nextToken();
        }
        public int[] intArr(int n) throws IOException {
            int[]in=new int[n];for(int i=0;i<n;i++)in[i]=nextInt();
            return in;
        }
        public long[] longArr(int n) throws IOException {
            long[]in=new long[n];for(int i=0;i<n;i++)in[i]=nextLong();
            return in;
        }
        public int[] intSortedArr(int n) throws IOException {
            int[]in=new int[n];for(int i=0;i<n;i++)in[i]=nextInt();
            shuffle(in);
            Arrays.sort(in);
            return in;
        }
        public long[] longSortedArr(int n) throws IOException {
            long[]in=new long[n];for(int i=0;i<n;i++)in[i]=nextLong();
            shuffle(in);
            Arrays.sort(in);
            return in;
        }
        public Integer[] IntegerArr(int n) throws IOException {
            Integer[]in=new Integer[n];for(int i=0;i<n;i++)in[i]=nextInt();
            return in;
        }
        public Long[] LongArr(int n) throws IOException {
            Long[]in=new Long[n];for(int i=0;i<n;i++)in[i]=nextLong();
            return in;
        }
        public String nextLine() throws IOException {
            return br.readLine();
        }

        public int nextInt() throws IOException {
            return Integer.parseInt(next());
        }

        public double nextDouble() throws IOException {
            return Double.parseDouble(next());
        }

        public char nextChar() throws IOException {
            return next().charAt(0);
        }

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

        public boolean ready() throws IOException {
            return br.ready();
        }

        public void waitForInput() throws InterruptedException {
            Thread.sleep(3000);
        }
    }
    static void shuffle(int[]in) {
        for(int i=0;i<in.length;i++) {
            int idx=(int)(Math.random()*in.length);
            int tmp=in[i];
            in[i]=in[idx];
            in[idx]=tmp;
        }
    }
    static void shuffle(long[]in) {
        for(int i=0;i<in.length;i++) {
            int idx=(int)(Math.random()*in.length);
            long tmp=in[i];
            in[i]=in[idx];
            in[idx]=tmp;
        }
    }
}


Measured memory_bytes: 54956