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: Accepted)

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
	
		Scanner scan = new Scanner(System.in);

		
		int X = scan.nextInt();
		int t = scan.nextInt();
		int ans = X - t;
		if(ans<=0) {
			System.out.println("0");
		}else {
			System.out.println(ans);
		}
		
		
		/*for(int i = 0; i <= A; i++) {
			for(int j = 0; j < A; j++) {
				System.out.print("☆");
				
			}
			System.out.println("");
		}*/
		
	}

}