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 Go (1.6) (judge verdict: Accepted)

// Package main provides
//
// File:  a.go
// Author: ymiyamoto
//
// Created on Wed Jan  9 00:30:57 2019
//
package main

import (
	"fmt"
	"sort"
)

func max(slice ...int) int {
	sort.Ints(slice)
	return slice[len(slice)-1]
}

func main() {
	var X, t int
	fmt.Scan(&X, &t)

	fmt.Println(max(X-t, 0))
}