import java.lang.*;
import java.io.*;
import niceIO.*;
import java.util.*;


public class gpc {

  public File fi;
  private FileInputStream fis;
  private niceInputStream f;
  private char EOF= ((char)(-1));
  private int left=0, right=1, tot=5, ind;
  private String LR[][] = new String[2][ind];

  public static void main(String argv[]) {
    pc P = new gpc(); 
  }

  public gpc() { char c;  String word=""; int i=0;
  /* UPDATE */
    System.out.print("File name:");
    String n= new String(les.ordBS());
    fi = new File(n);
    try{ fis = new FileInputStream(fi); f= new niceInputStream(fis);
      c= f.tegnNB();
      Stack st= new Stack(); Stack cnt= new Stack();
      while (c != EOF) { 
	if (c=='(') { word= f.ordBS(); 
	  st.push(new String("(")); cnt.push(new Integer(f.LineNo())); 
	  while (!st.isEmpty() && c != EOF) {
	    c= f.tegnNB(); 
	    if (c=='(') {st.push(new String("("));cnt.push(new Integer(f.LineNo())); }
	    else if (c==')') {st.pop(); cnt.pop();}
	  }
	  if (c == EOF && !st.isEmpty()) { 
	    System.out.print("Unmached '(' at line: "+cnt.peek());
	    cnt.pop();
	    while (!cnt.isEmpty()) {
	      System.out.print(", "+cnt.peek()); cnt.pop();}
	    System.out.print("\n");
	  }
	  else {
	    i= (i+1) % 2;
	    if (i==1) System.out.print(word+" ");
	    else System.out.println("-> "+word); }
	} 
	else if (c==')') System.out.println("Opening ')' at line: "+f.LineNo());
	c= f.tegnNB();
      }
    } catch(FileNotFoundException e){System.out.println("No file `"+n+"'");}
  }

  public void getLR() {
    String l= les.ordBS(); ind=-1;
    while (l != "" && ind<tot-1) {
      ind= ind+1;
      if (ind<tot) { LR[left][ind] = l; LR[right][ind]= les.ordBS(); l=les.ordBS();}
      else System.out.println("Can have at most 5 pairs - finish!");
    }
  }

  public boolean okLR(String l,String r) {
    int k=ind+1;
    for (int i=0; i<ind; i++) {if (LR[right][i]==r) k=i;}
    if (k>ind) return false;
    else if (LR[left][k]=l) return true;
    else return false;
  }

}