import sys, math, itertools, functools, collections
input = sys.stdin.readline

def solve(testcase):
    def ans(x):
        return x * (x+1) // 2 * 26
    n = int(input())
    low, high = 0, 1000000
    while low != high:
        mid = (low+high) >> 1
        if ans(mid) >= n:
            high = mid
        else:
            low = mid+1
    n -= ans(low-1)
    cur = (n-1) // low
    print('Case #'+str(testcase)+':', chr(65+cur))


for testcase in range(1, int(input())+1):
    solve(testcase)