public class StringConcatenation
{
	public static void main(String[] args)
	{
		
		String str1="Hello";
		String str2="Jello";
		
		String str3=str1+" "+str2;
	
		System.out.println(str3);
	
		
		String str;
		int i;
		i=0;
		str="";
		str=str+i;
		str=str+i;
		
		System.out.println(str);
	}
}