private boolean check(String data)
	{
		if (data == "")
		{
			return true;
		}
		
		int tmp = this.getValueFromString(data.toCharArray());
		
		if (tmp > this.end || data.length() > this.max_length)
		{
			return false;
		}
		
		if (tmp >= this.start)
		{
			if (data.charAt(0) != '0')
			{			
				if (this.isPrime(tmp))
				{
					this.answers.add(tmp);
				}
			}
		}
			
		return true;
	}