import java.io.BufferedReader;
import java.io.FileReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.math.BigInteger;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.StringTokenizer;

public class Main {
    final static long MOD = 1000000007;

    public static void main(String args[]) {
        FastScanner fs = new FastScanner();
        PrintWriter out = new PrintWriter(System.out);

        int n = fs.nextInt();
        int [][] input = new int[n][3];
        for(int i = 0; i < n; i++) {
            input[i] = fs.nextIntArray(3);
        }
        int [][] dp = new int[n][3];
        dp[0][0] = input[0][0];
        dp[0][1] = input[0][1];
        dp[0][2] = input[0][2];
        int lastC = -1;
        for(int i = 1; i < n; i++) {
            for(int j = 0; j < 3; j++) {
                int maxValue = Integer.MIN_VALUE;
               for(int k = 0; k < 3; k++) {
                   if(k != j && maxValue < dp[i-1][k] + input[i][j]) {
                       maxValue = dp[i - 1][k] + input[i][j];
                   }
                   dp[i][j] = maxValue;
               }
            }
        }
        out.println(Math.max(dp[n-1][0], Math.max(dp[n-1][1], dp[n-1][2])));
        out.flush();
        out.close();
    }

    static class FastScanner {
        BufferedReader br;
        StringTokenizer st;

        public FastScanner() {
            try {
                br = new BufferedReader(new InputStreamReader(System.in));
                //                br = new BufferedReader(new FileReader("file2.txt"));

                st = new StringTokenizer("");
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        public String next() {
            if (st.hasMoreTokens())
                return st.nextToken();
            try {
                st = new StringTokenizer(br.readLine());
            } catch (Exception e) {
                e.printStackTrace();
            }
            return st.nextToken();
        }

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

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

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

        public String nextLine() {
            String line = "";
            try {
                line = br.readLine();
            } catch (Exception e) {
                e.printStackTrace();
            }
            return line;
        }

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

        public Integer[] nextIntegerArray(int n) {
            Integer[] a = new Integer[n];
            for (int i = 0; i < n; i++)
                a[i] = nextInt();
            return a;
        }

        public int[] nextIntArray(int n) {
            int[] a = new int[n];
            for (int i = 0; i < n; i++)
                a[i] = nextInt();
            return a;
        }

        public long[] nextLongArray(int n) {
            long[] a = new long[n];
            for (int i = 0; i < n; i++)
                a[i] = nextLong();
            return a;
        }

        public char[] nextCharArray() {
            return nextLine().toCharArray();
        }
    }

}




Measured memory_bytes: 51284