def factor(x):
    i = 2
    while i * i < x:
        if x % i == 0:
            return i
        i += 1
    return -1

N = input()
p = factor(N)
if p < 0:
    print('NO')
    quit()
p = factor(N)
if p < 0:
    print('NO')
    quit()
print('YES')