AscII Art

#include <bits/stdc++.h>
using namespace std;
using ll = long long int;
void solve() {

    ll x; cin >> x;
    x--;
    int i = 1;
    while(x >= 26*i) {
        x -= 26*i;
        i++;
    }

    cout << char('A' + x/i) << '\n';
}

int main() {
    int q; cin >> q;
    for(int i=1; i<=q; ++i) {
        cout << "Case #" << i << ": ";
        solve();
    }
    return 0;
}