def digit_sum(number):
return sum(map(int, str(number)))
print(digit_sum(int(input(
assert digit_sum(1222) == 7
assert digit_sum(555) == 15
assert digit_sum(987654321) == 45
def digit_sum(number):
return sum(map(int, str(number)))
print(digit_sum(int(input(
assert digit_sum(1222) == 7
assert digit_sum(555) == 15
assert digit_sum(987654321) == 45