import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.FilterInputStream;
import java.io.BufferedInputStream;
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;
        ScanReader in = new ScanReader(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, ScanReader in, PrintWriter out) {
            int n = in.scanInt();
            long po[][] = new long[n][3];
            for (int i = 0; i < n; i++) po[i] = new long[]{in.scanLong(), in.scanLong(), in.scanLong()};
            long dp[][] = new long[n][3];


            dp[0][0] = po[0][0];
            dp[0][1] = po[0][1];
            dp[0][2] = po[0][2];


            for (int i = 1; i < n; i++) {
                for (int j = 0; j < 3; j++) {
                    for (int k = 0; k < 3; k++) {
                        if (k != j) dp[i][j] = Math.max(dp[i][j], dp[i - 1][k] + po[i][j]);
                    }
                }
            }

            out.println(Math.max(Math.max(dp[n - 1][0], dp[n - 1][1]), dp[n - 1][2]));
        }

    }

    static class ScanReader {
        private byte[] buf = new byte[4 * 1024];
        private int INDEX;
        private BufferedInputStream in;
        private int TOTAL;

        public ScanReader(InputStream inputStream) {
            in = new BufferedInputStream(inputStream);
        }

        private int scan() {
            if (INDEX >= TOTAL) {
                INDEX = 0;
                try {
                    TOTAL = in.read(buf);
                } catch (Exception e) {
                    e.printStackTrace();
                }
                if (TOTAL <= 0) return -1;
            }
            return buf[INDEX++];
        }

        public int scanInt() {
            int I = 0;
            int n = scan();
            while (isWhiteSpace(n)) n = scan();
            int neg = 1;
            if (n == '-') {
                neg = -1;
                n = scan();
            }
            while (!isWhiteSpace(n)) {
                if (n >= '0' && n <= '9') {
                    I *= 10;
                    I += n - '0';
                    n = scan();
                }
            }
            return neg * I;
        }

        private boolean isWhiteSpace(int n) {
            if (n == ' ' || n == '\n' || n == '\r' || n == '\t' || n == -1) return true;
            else return false;
        }

        public long scanLong() {
            long I = 0;
            int n = scan();
            while (isWhiteSpace(n)) n = scan();
            int neg = 1;
            if (n == '-') {
                neg = -1;
                n = scan();
            }
            while (!isWhiteSpace(n)) {
                if (n >= '0' && n <= '9') {
                    I *= 10;
                    I += n - '0';
                    n = scan();
                }
            }
            return neg * I;
        }

    }
}



Measured memory_bytes: 35668