def find_num(*args):
i = 0
lists = list()
if len(args) >0 :
if int(args[0])%7==0 and (args[0])%3==0:
print("{}能被3和7
整除".format(*args))
else:
print("{}能被3和7整除".format(*args))
while i<=1000:
if i%7==0 and i%3==0:
lists.append(i)
i+=1
return lists
find_num(21)
result = find_num()
print("1000以内能被7和3整除的数:")
print(result)