def solve():
target = 4
limit = 150000
n_prime_divisors = [0] * limit
run_length = 0
for n in range(2, limit):
if n_prime_divisors[n] == 0:
for m in range(2 * n, limit, n):
n_prime_divisors[m] += 1
run_length = 0
elif n_prime_divisors[n] == target:
run_length += 1
else:
run_length = 0
if run_length == target:
return n - target + 1
n = solve()
print(n)