public class Symbol {
  public static final int NL = 0, EOF = 1, IDENT = 2, ICONST = 3,
    LPAR = 4, RPAR = 5, LT = 6, GT = 7, LBRA = 8, RBRA = 9,
    ASSIGN = 10, SEMI = 11, READ = 12, PRINT = 13, IF = 14,
    Program = 15, StatList = 16, Stat = 17, Cond = 18, Expr = 19;
  public static final int N = 15;
}

%%
%class Lexer
%int
L = [A-Za-z_]
D = [0-9]
Ident = {L}({L}|{D})*
Iconst = [-+]?{D}+
Blank = [ \t\n]+
%%
{Blank}   { /* ignore */ }
\(        { return Symbol.LPAR; }
\)        { return Symbol.RPAR; }
;         { return Symbol.SEMI; }
\{        { return Symbol.LBRA; }
\}        { return Symbol.RBRA; }
=         { return Symbol.ASSIGN; }
\>        { return Symbol.GT; }
\<        { return Symbol.LT; }
read      { return Symbol.READ; }
print     { return Symbol.PRINT; }
if        { return Symbol.IF; }
{Ident}   { return Symbol.IDENT; }
{Iconst}  { return Symbol.ICONST; }

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

public class Sam61 {
  static int[][] rules = {
    { },
    { Symbol.Program, Symbol.StatList }, //1
    { Symbol.StatList, Symbol.Stat, Symbol.StatList }, //2
    { Symbol.StatList }, //3
    { Symbol.Stat, Symbol.IDENT, Symbol.ASSIGN, Symbol.Expr, Symbol.SEMI },//4
    { Symbol.Stat, Symbol.READ, Symbol.IDENT, Symbol.SEMI }, //5
    { Symbol.Stat, Symbol.PRINT, Symbol.Expr, Symbol.SEMI }, //6
    { Symbol.Stat, Symbol.IF, Symbol.LPAR, Symbol.Cond,
                   Symbol.RPAR, Symbol.Stat }, //7
    { Symbol.Stat, Symbol.LBRA, Symbol.StatList, Symbol.RBRA }, //8
    { Symbol.Cond, Symbol.Expr, Symbol.LT, Symbol.Expr }, //9
    { Symbol.Cond, Symbol.Expr, Symbol.GT, Symbol.Expr }, //10
    { Symbol.Expr, Symbol.IDENT }, //11
    { Symbol.Expr, Symbol.ICONST }, //12
  };
  static int [][] ptab = {
    {},{},{},{}, {},{},{},{}, {},{},{},{}, {},{},{},
    { 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 1 },
    { 0, 3, 2, 0, 0, 0, 0, 0, 2, 3, 0, 0, 2, 2, 2 },
    { 0, 0, 4, 0, 0, 0, 0, 0, 8, 0, 0, 0, 5, 6, 7 },
    { 0, 0, 9, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
    { 0, 0,11,12, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
  };
  public static void main(String[] args) throws Exception {
    Tokenizer tok = new Tokenizer(args[0]);
    Stack<Integer> stk = new Stack<Integer>();
    stk.push(Symbol.Program);
    while(stk.size() > 0) {
//      System.out.printf("%s : %s\n", stk.toString(), tok.curStr());
      if(stk.peek() < Symbol.N) {
        if(!tok.chkfwd(stk.pop())) {
          System.err.printf("token mismatch: %s at %d\n",
            tok.curStr(), tok.curLine()); return;
        }
      } else {
        int t = tok.curTok(); if(tok.isEof()) { t = Symbol.EOF; }
        int r = ptab[stk.peek()][t];
        if(r == 0) {
          System.err.printf("cannot determine rule for %d: %s at %d\n",
            stk.peek(), tok.curStr(), tok.curLine()); return;
        }
        System.out.printf("rule: %d\n", r);
        int[] a = rules[r];
        stk.pop();
        for(int i = a.length-1; i > 0; --i) { stk.push(a[i]); }
      }
    }
  }
}
class Tokenizer {
  Lexer lex;
  int tok, line = 1;
  boolean eof = false;
  public Tokenizer(String s) throws Exception {
    lex = new Lexer(new FileReader(s));
    tok = lex.yylex();
  }
  public boolean isEof() { return tok == Lexer.YYEOF; }
  public int curTok() { return tok; }
  public String curStr() { return lex.yytext(); }
  public int curLine() { return line; }
  public boolean chk(int t) { return tok == t; }
  public void fwd() {
    if(isEof()) { return; }
    try {
      tok = lex.yylex();
      while(tok == Symbol.NL) { ++line; tok = lex.yylex(); }
    } catch(IOException ex) { tok = Lexer.YYEOF; }
  }
  public boolean chkfwd(int t) {
    if(chk(t)) { fwd(); return true; } else { return false; }
  }
}

read x; read y; if(x > y) { z = x; x = y; y = z; } print x; print y;