python3 数论 找素数
st = [1 for i in range(16010)]
primes = []
def euler(n):
m = int(n**0.5)
for i in range(2, n+1):
if st[i] == 1:
primes.append(i)
for j in primes:
if i * j > n:
break
st[i * j] = 0
if i % j == 0:
break
euler(16000)
for i in range(1, 10000000111):
n = int(input())
if n <= 0:
break
elif n == 1 or n == 2:
print(f"{i}: no")
elif n in primes:
print(f"{i}: yes")
else:
print(f"{i}: no")