#include<stdio.h>
int main(){
int N;
//int count=0;
  
  scanf("%d",&N);
  while(N>0)
  N-=1000;
 
  printf("%d",-N);
}
### Prompt

Construct a cpp code solution to the problem outlined:

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<stdio.h>
int main(){
int N;
//int count=0;
  
  scanf("%d",&N);
  while(N>0)
  N-=1000;
 
  printf("%d",-N);
}
```