LookAndSay sequence implementation in Java

LookAndSay.java

package com.eliblaney.lookandsay;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class LookAndSay {
	
	// Usage: [total]
	public static void main(String... args) {
		int total = 10;
		try {
			if(args.length > 0)
				total = Integer.parseInt(args[0]);
		} catch(NumberFormatException e) {
			System.err.println("Argument 1 must be an integer: [total]");
			return;
		}		
		
		InputStreamReader ir = new InputStreamReader(System.in);
		BufferedReader r = new BufferedReader(ir);
		
		System.out.print("First number: ");
		String num = null;
		do {
			if(num != null) {
				System.out.print("Invalid number, please type a number: ");
				main(args);
			}
			
			try {
				num = r.readLine();
			} catch(IOException e) {
				System.err.println("Could not read input");
				e.printStackTrace();
				return;
			}
		} while(!num.matches("^\\d+$"));
		
		System.out.println(num);
		LookAndSay sequence = new LookAndSay(num);
		for(int i = 0; i < total; i++) {
			System.out.println(sequence.next());
		}
		
		try {
			r.close();
			ir.close();
		} catch(IOException e) {
			System.err.println("Could not close readers");
			e.printStackTrace();
		}
	}
	
	private String num;
	
	public LookAndSay(String start) {
		this.num = start;
	}
	
	public String next() {
		String ret = "";
		char n = '*';
		int count = 1;
		for(char c : this.num.toCharArray()) {
			if(c == n)
				count++;
			else {
				ret += count + "" + n;
				n = c;
				count = 1;
			}
		}
		ret = (ret + count + "" + n).substring(2);
		return this.num = ret;
	}
}