n = int(input())
def is_prime(n):if n < 2:return Falsefor i in range(2, int(n**0.5) + 1):if n % i == 0:return Falsereturn True
if is_prime(n):print("YES")else:print("NO")
n = int(input())
def is_prime(n):
if n < 2:
return False
for i in range(2, int(n**0.5) + 1):
if n % i == 0:
return False
return True
if is_prime(n):
print("YES")
else:
print("NO")