class Decode 
{
	String str;
	int key;
	Code cd;
	Decode(String s,int i)
	{
		str=s;key=i;cd=new Code(key);
	}
	String convert()
	{
		String s="";
		char[] array=str.toCharArray();
		for (int i=0;i<array.length ;i++ )
		{
			s+=change(array[i]);
		}
		return s;
	}
	char change(char ch)
	{
		return cd.de(ch);
	}
}