Problem:
Score : 200 points

Problem Statement

You are given positive integers A and B.

Find the K-th largest positive integer that divides both A and B.

The input guarantees that there exists such a number.

Constraints

All values in input are integers.

1 \leq A, B \leq 100

The K-th largest positive integer that divides both A and B exists.

K \geq 1

Input

Input is given from Standard Input in the following format:

A B K

Output

Print the K-th largest positive integer that divides both A and B.

Sample Input 1

8 12 2

Sample Output 1

2

Three positive integers divides both 8 and 12: 1, 2 and 4.
Among them, the second largest is 2.

Sample Input 2

100 50 4

Sample Output 2

5

Sample Input 3

1 1 1

Sample Output 3

1

Solution in Python (3.4.3) (judge verdict: Accepted)



a,b,k = map(int, input().split())

def divisor(n): #nの約数を全て求める
  i = 1
  table = []
  while i * i <= n:
    if n%i == 0:
      table.append(i)
      table.append(n//i)
    i += 1
  return set(table)

ad=divisor(a)
bd=divisor(b)

abd = list(set(ad & bd))
abd.sort()

print(abd[-k])