#include<bits/stdc++.h>
using namespace std;
string trans(int b,int n)
{

    string s="";
    while(n!=0)
    {   char l=(n%b)+'0'; int c=n%b;

        if(c==10)s='A'+s;
        else if(c==11)s='B'+s;
        else if(c==12)s='C'+s;
        else if(c==13)s='D'+s;
        else if(c==14)s='E'+s;
        else if(c==15)s='F'+s;
        else {s=l+s;}
        n=n/b;
    }

    return s;


}
int main()
{


int t;
cin>>t; int b,n;
for(int i=1;i<=t;i++)
{

  cin>>b>>n;
   if(b>n)cout<<"Case "<<i<<": "<<trans(n,b)<<endl;
   else {cout<<"Case "<<i<<": "<<trans(b,n)<<endl;}




}


}