蓝桥杯备考：签到题之糖果

#include <iostream>
using namespace std;

int n,k;
int main()
{
	cin >> n >> k;
	if(n%k)
	{
		int t= n%k;
		int ret = k-t;
		cout << ret;
	}
	else
	{
		cout << k;
	}
	
	
	
	
	
	
	
	return 0;
}