#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
ll findTrailingZeros(ll n)
{

    int count = 0;
    for (int i = 5; n / i >= 1; i *= 5)
        count += n / i;

    return count;
}
int main()
{
    ll t,n,l,h,c,m;
    cin>>t;
    c=1;
    while(t--)
    {
        cin>>n;
        l=0,h=ll(1e18+9);
        while (l <= h) {
         m = (l + h) / 2;
        if (findTrailingZeros(m)< n)
            l = m + 1;
        else
            h = m - 1;
    }
    if(findTrailingZeros(m)!=n)printf("Case %d: impossible\n",c++);
      else printf("Case %d: %lld\n",c++,m)  ;
    }
    return 0;
}