> #include<iostream>
> using namespace std;
> int mod(int a,int b)
> {
> 	int z;
> 	z=a%b;
> 	return z;
> }
> int main()
> {
> 	int a,b;
> 	while(cin>>a>>b)
> 	{
> 		cout<<mod(a,b)<<endl;
> 	}
> }