chk = [0,0,1]+[1]*6000
primes = []
for i in range(2, 5500):
if chk[i]:
primes.append(i)
for j in range(2*i, 5500, i):
chk[j] = 0
z = []
for i in range(len(primes)-1):
z.append(primes[i]*primes[i+1])
n = int(input())
for i in z:
if i > n:
print(i)
break