Language: Java

java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.*;

public class Main {
    public static void main(String[] args) {
        PrintWriter out = new PrintWriter(System.out);
        InputStreamScanner in = new InputStreamScanner(System.in);
        new Main().solve(in, out);
        out.flush();
    }

    private void solve(InputStreamScanner in, PrintWriter out) {
        int n = in.nextInt();
        int[][] a = new int[3][n + 1];
        for (int i = 1; i <= n; i++) {
            a[0][i] = in.nextInt();
            a[1][i] = in.nextInt();
            a[2][i] = in.nextInt();
        }

        int[][] dp = new int[3][n + 1];
        dp[0][1] = a[0][1];
        dp[1][1] = a[1][1];
        dp[2][1] = a[2][1];

        for (int i = 1; i < n; i++) {
            for (int j = 0; j < 3; j++) {
                for (int k = 0; k < 3; k++) {
                    if (j == k) {
                        continue;
                    }

                    if (dp[j][i] + a[k][i + 1] > dp[k][i + 1]) {
                        dp[k][i + 1] = dp[j][i] + a[k][i + 1];
                    }
                }
            }
        }

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

    static class InputStreamScanner {

        private InputStream in;

        private byte[] buf = new byte[1024];
        private int len = 0;
        private int off = 0;

        InputStreamScanner(InputStream in)	{
            this.in = in;
        }

        String next() {
            StringBuilder sb = new StringBuilder();
            for (int b = skip(); !isSpace(b);){
                sb.appendCodePoint(b);
                b = read();
            }
            return sb.toString();
        }

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

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

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

        char nextChar() {
            return (char)skip();
        }

        int skip() {
            for (int b; (b = read()) != -1;) {
                if (!isSpace(b)) {
                    return b;
                }
            }
            return -1;
        }

        private boolean isSpace(int c) {
            return c < 33 || c > 126;
        }

        private int read() {
            if (len == -1) {
                throw new InputMismatchException("End of Input");
            }
            if (off >= len){
                off = 0;
                try {
                    len = in.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException(e.getMessage());
                }
                if (len <= 0) {
                    return -1;
                }
            }
            return buf[off++];
        }
    }
}

Compiler output:
Main.java:1: error: class, interface, enum, or record expected
java.io.IOException;
^
Main.java:2: error: class, interface, enum, or record expected
import java.io.InputStream;
^
Main.java:3: error: class, interface, enum, or record expected
import java.io.PrintWriter;
^
Main.java:4: error: class, interface, enum, or record expected
import java.util.*;
^
4 errors