#include<bits/stdc++.h>
using namespace std;

typedef long long ll;

#define PI acos(-1.0)
#define MX 1000000
#define MOD 1000000007

map<ll,ll>mymap;
#define ff first
#define ss second

ll dp[MX];

ll sumFactors(ll x)
{
    ll LIM = sqrt(x);
    ll sum = 1;
    for(ll i=2 ; i<=LIM ; i++){
        if(x%i == 0){
           ll a = i;
           ll b = x/i;

           if(a != b) sum+=(a+b);
           else sum+=a;
        }
    }
    return sum;
}

int main()
{
    ll n,a,b,i,j,k,t,tc=1;

    for(i=220; i<MX ;i++){
        ll sum = sumFactors(i);
        if(i!=sum) mymap[i] = sum;
    }

    for(auto i:mymap){
        if(mymap[i.ss] == i.ff)
            dp[i.ff] = i.ss;
    }

    cin>>t;


    while(t--){
        cin>>a>>b;

        cout<<"Case "<<tc++<<':'<<endl;

        for(i=a ; ;i++){
            if(dp[i] > b || i > b) break;

            if(dp[i]){
                cout<<i<<' '<<dp[i]<<endl;
                j = i;
                i= dp[i];

            }
            if(dp[j] == b) break;
        }
    }


    return 0;
}