import math
n=int(input())
zhishu=True
if n==1:
    print("No")
elif n==2 or n==3:
    print("Yes")
elif n>3:
    i=3;
    while(i<=int(math.sqrt(n))+1):
        if n%i==0:
            print("No")
            zhishu=False
            break
        i+=2;
    if zhishu:
        print("Yes")