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)