{}
def is_prime(n):
s = 0
for d in range(1, n + 1):
if n % d == 0:
if s>2:
break
s += 1
if s == 2:
return True
else:
return False
while True:
n= int(input("Enter a number :"))
if n<=1:
print(n, "is neither prime nor composite.")
elif is_prime(n):
print(n, "is a prime number.")
else:
print(n, "is not a prime number.")
ch= int(input("\nDo you want to retest? \n1 for yes\n2 for no :"))
if ch == 2:
break