#include<bits/stdc++.h>
using namespace std;
typedef long long int ll;
bool mark[2750000+5];
vector<ll>isprime;
ll psize;

void sieve()
{
    ll i,j;
    mark[0]=true;
    mark[1]=true;
    for(i=2;i*i<=2750000;i++)
    {
        if(mark[i]==false)
        {
            for(j=i*i;j<=2750000;j+=i)
            {
                mark[j]=true;
            }
        }
    }
   // isprime.push_back(2);
    for(i=2;i<=2750000;i++)
    {
        if(mark[i]==false)
            isprime.push_back(i);
    }
}


ll cnt(ll n)
{
     //sieve();
     ll res=0,i;

     for(i=0;isprime[i]*isprime[i]<=n && i<=isprime.size();i++)
     {
         if(n%isprime[i]==0)
         {
             while(n%isprime[i]==0)
             {
                 res++;
                 n/=isprime[i];
             }
         }
     }
     if(n>1)
        res++;
     return res;
}

ll arr[2750000+5];
int main()
{
    sieve();
    arr[0]=0,arr[1]=0;
    for(ll i=2;i<2750000;i++)
    {
        arr[i]=arr[i-1]+cnt(i);
    }
   // cout<<arr[1305757]<<endl;
    ll n,cas=1;
   while(cin>>n)
    {
        if(n<0)
            break;
       ll a=lower_bound(arr,arr+2750000,n)-arr;
        if(arr[a]==n)
            cout<<"Case "<<cas++<<": "<<a<<"!"<<endl;
        else
            cout<<"Case "<<cas++<<": Not possible."<<endl;

    }
    return 0;
}