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