---
# System prepended metadata

title: Untitled

---


a=input()
b=10
while b>0:
    if a.isdigit() and int(a)<=1000:
        a=int(a)
        break
    elif a.isdigit():
        a=input("數字大於1000請重新輸入")
    else :
        a=input("這不是數字請從新輸入")
        
if a%7==0:
    print(a,"是七的倍數")
else :
    print(a,"不是七的倍數")
                