def make_divisors(n):
    lower_divisors,upper_divisors=[],[]
    i=1
    while i*i<=n:
        if n%i==0:
            lower_divisors.append(i)
            if i!=n//i:
                upper_divisors.append(n//i)
        i+=1
    return lower_divisors+upper_divisors[::-1]

n=int(input())
for i in range(n-100,n+101):
    lis=make_divisors(i)
    if len(lis)>=3:
        print(i)
        break