#include <bits/stdc++.h>
using namespace std ;
typedef long long ll;
ll count_5(ll num)
{
ll pow_5=5,counter=0;
while(pow_5<=num)
{
counter+=num/pow_5;
pow_5*=5;
}
//cout<<counter<<endl;
return counter;
}
ll binary_s(ll n)
{
int low=0,high=1000000000,mid,ans=0;
while (low<=high)
{
mid=(low+high)/2 ;
ll tmp=count_5(mid);
if (tmp<n)
low=mid+1;
else if(tmp>n)
high=mid-1;
else
{
ans=mid;
high=mid-1;
}
}
return ans ;
}
int main ()
{
ll i,j,k,l,m,n,test;
cin>>test;
for (k=1;k<=test;k++)
{
cin>>n;
ll ans=binary_s(n);
if(ans==0)
cout<<"Case "<<k<<": "<<"impossible"<<endl;
else
cout<<"Case "<<k<<": "<<ans<<endl;
}
return 0 ;
}
using namespace std ;
typedef long long ll;
ll count_5(ll num)
{
ll pow_5=5,counter=0;
while(pow_5<=num)
{
counter+=num/pow_5;
pow_5*=5;
}
//cout<<counter<<endl;
return counter;
}
ll binary_s(ll n)
{
int low=0,high=1000000000,mid,ans=0;
while (low<=high)
{
mid=(low+high)/2 ;
ll tmp=count_5(mid);
if (tmp<n)
low=mid+1;
else if(tmp>n)
high=mid-1;
else
{
ans=mid;
high=mid-1;
}
}
return ans ;
}
int main ()
{
ll i,j,k,l,m,n,test;
cin>>test;
for (k=1;k<=test;k++)
{
cin>>n;
ll ans=binary_s(n);
if(ans==0)
cout<<"Case "<<k<<": "<<"impossible"<<endl;
else
cout<<"Case "<<k<<": "<<ans<<endl;
}
return 0 ;
}