class P04_intOverflow {
	
	public static void main(String[] args)
	{
		//int type can hold 2123123123.  However, 2123123123+2123123123 is too big for int.
		System.out.println(2123123123); //Output is OK: 2123123123
		
		long x;
		x = 2123123123 + 2123123123;
		System.out.println(x); //Wrong Output: -48721050 

	}
}

/*

Question: x is long.  Why the result is still overflow?

Answer: 
	* First step : "2123123123 + 2123123123"
	* Second step : set the value of x
	*
	Here, the data type of x is not concerned in the first step.
	That is, whether x is int or long, does not affect the first step.
	
	Because nNumbers like "2123123123" is by default treated as int.
	Therefore "2123123123 + 2123123123" is operated in int mode.

*/