#include<cstdio>
int n;
int main() {
	scanf("%d",&n);
	n-=(n/1000)*1000;
	if (n) n=1000-n;
	printf("%d",n);
	return 0;
} 
### Prompt

In cpp, your task is to solve the following problem:

We will buy a product for N yen (the currency of Japan) at a shop.

If we use only 1000-yen bills to pay the price, how much change will we receive?

Assume we use the minimum number of bills required.

Constraints

* 1 \leq N \leq 10000
* N is an integer.

Input

Input is given from Standard Input in the following format:


N


Output

Print the amount of change as an integer.

Examples

Input

1900


Output

100


Input

3000


Output

0

### Response

```cpp
#include<cstdio>
int n;
int main() {
	scanf("%d",&n);
	n-=(n/1000)*1000;
	if (n) n=1000-n;
	printf("%d",n);
	return 0;
} 
```