In the online judge system, a judge file may include multiple datasets to check whether the submitted program outputs a correct answer for each test case. This task is to practice solving a problem with multiple datasets.  Write a program which reads an integer x and print it as is. Note that multiple datasets are given for this problem.
import sys

l = sys.stdin.readlines()
ll = len(l)
for i in range(1,ll+1):
    print(f"Case {i}: " + str(l[i-1]),end="")

i = 1
while True:
    x = int(input())
    if x == 0:
        break
    print(f"Case {i}: " + str(x))
    i = i + 1

