Vorlage für SOI-Aufgaben

import sys
 
 
def subtask1(testcase):
    basket_count = int(input(''))
    items = input('').split()
    total_items = 0
    for i in range(basket_count):
        total_items += int(items[i])
 
    if total_items % basket_count == 0:
        print(f'Case #{testcase}: YES')
    else:
        print(f'Case #{testcase}: NO')
 
 
if __name__ == '__main__':
    original_stdin = sys.stdin
    sys.stdin = open('input0.txt', 'r')
 
    original_stdout = sys.stdout
    sys.stdout = open('output0.txt', 'w')
 
    number = int(input(''))
    for testcase in range(number):
        subtask1(testcase)