import sys
input = sys.stdin.readline
from collections import deque
from bisect import bisect_left, bisect_right
import itertools
#from math import *

for t in range(1, int(input())+1):

    n = int(input())
    c = 26
    a = 0
    while a+c < n:
        a += c
        c += 26
    u = (n-a+c//26-1)//(c//26)
    print("Case #{}: {}".format(t, chr(u+64)))