import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.InputMismatchException;
import java.io.IOException;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        CVacation solver = new CVacation();
        solver.solve(1, in, out);
        out.close();
    }

    static class CVacation {
        public void solve(int testNumber, InputReader in, PrintWriter out) {
            int N = in.nextInt();
            int[][] inf = new int[N][3];
            for (int i = 0; i < N; ++i) {
                inf[i][0] = in.nextInt();
                inf[i][1] = in.nextInt();
                inf[i][2] = in.nextInt();
            }
            int[][] dp = new int[N][3];
            for (int i = 0; i < N; i++) {
                for (int j = 0; j < 3; j++) {
                    dp[i][j] = -1;
                }
            }
            out.print(rec(0, -1, inf, dp));
        }

        int rec(int n, int prev, int[][] inf, int[][] dp) {
            if (n == inf.length) {
                return 0;
            }
            if (prev != -1 && dp[n][prev] != -1) {
                return dp[n][prev];
            } else {
                int z = 0;
                for (int i = 0; i < 3; i++) {
                    if (i != prev) z = Math.max(z, inf[n][i] + rec(n + 1, i, inf, dp));
                }
                return (prev == -1) ? z : (dp[n][prev] = z);
            }
        }

    }

    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1)
                throw new InputMismatchException();
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0)
                    return -1;
            }
            return buf[curChar++];
        }

        public int nextInt() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        private boolean isSpaceChar(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

    }
}



Measured memory_bytes: 43220