#include<map>
#include<set>
#include<cmath>
#include<queue>
#include<stack>
#include<vector>
#include<cstdio>
#include<cassert>
#include<iomanip>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#define C 0.5772156649
#define pi acos(-1.0)
#define ll long long
#define mod 1000000007
#define ls l,m,rt<<1
#define rs m+1,r,rt<<1|1
#pragma comment(linker, "/STACK:1024000000,1024000000")using namespace std;const double g=10.0,eps=1e-7;
const int N=100000+10,maxn=500+100,inf=0x3f3f3f;ll getzero(ll k)
{ll ans=0;while(k){ans+=k/5;k/=5;}return ans;
}
int main()
{ios::sync_with_stdio(false);cin.tie(0);ll t,cnt=0;cin>>t;while(t--){ll n;cin>>n;ll l=1,r=500000000;while(l<=r){ll m=(l+r)/2;if(getzero(m)<n)l=m+1;else r=m-1;}if(getzero(l)==n)cout<<"Case "<<++cnt<<": "<<l<<endl;else cout<<"Case "<<++cnt<<": impossible"<<endl;}return 0;
}
/*********************
100000000
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*********************/