Woburn Challenge 2017-18 Round 3 - Junior Division
At last, your YouTube channel is really taking off in popularity! You currently have ~S~ ~(1 \le S \le 100)~ subscribers (you created an alternate account to give your channel at least ~1~ subscription).
To reward your dedicated viewers and encourage more subscriptions, you'd like to put out a special video when your subscriber count reaches the next "milestone" quantity larger than its current value. A milestone is a power of ~10~ (e.g. ~10~, ~100~, ~1\,000~, ~10\,000~, etc.). If ~S~ is already exactly equal to a power of ~10~, then you're interested in the next larger one.
Your subscriber count is quickly growing, and you'd like to estimate how much time you'll have to prepare your special video. As such, you'd like to determine the number of additional subscribers required to hit the next milestone count!
The first and only line of input consists of a single integer, ~S~.
Output a single integer, the number of additional subscribers required to hit the next milestone.
Sample Input 1
Sample Output 1
Sample Input 2
Sample Output 2
Sample Explanation 2
In the first case, the next milestone is ~10~ subscribers, which you'll
hit after gaining another ~4~ subscribers.
In the second case, the next milestone is ~100~ subscribers.