Problem:
Score : 100 points

Problem Statement

We have a sandglass that runs for X seconds. The sand drops from the upper bulb at a rate of 1 gram per second. That is, the upper bulb initially contains X grams of sand.

How many grams of sand will the upper bulb contains after t seconds?

Constraints

1≤X≤10^9

1≤t≤10^9

X and t are integers.

Input

The input is given from Standard Input in the following format:

X t

Output

Print the number of sand in the upper bulb after t second.

Sample Input 1

100 17

Sample Output 1

83

17 out of the initial 100 grams of sand will be consumed, resulting in 83 grams.

Sample Input 2

48 58

Sample Output 2

0

All 48 grams of sand will be gone, resulting in 0 grams.

Sample Input 3

1000000000 1000000000

Sample Output 3

0

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

//this library has many things needed for arrays, the asterisc means we get everything is inside, the dot says where is is inside, you need the ; to tell the line has ended, like in C
import java.util.*;

//the name of the main function has to be the same name of the program
//what public class mean in java: it means that other function scan also access the class. What happens if we dont make it public? Well, it stil works, but it will be visivle to code only in the same package
public class Main {
	//this is a method, it tells that it will execute the things that are inside, it takes string as args when we execute the program, it is optional. What if instead we use int? It does not work, it has to be String[] args
	public static void main(String[] args){
		//it is a class of the .util that is used to take input from the user. Why it is used as class?
		Scanner sc = new Scanner(System.in);
		// get a integer
		//nextInt is a method, it will take text and turn it into an integer. It is looking for space or line break? Yes, if it is a line break or a space it treats it the same way. How to consider it is different?
		int C = sc.nextInt();
		// get two integers separated with half-width break
		int t = sc.nextInt();
		System.out.println(C-t);
	}
}