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 (3.8.2) (judge verdict: Accepted)

#入力:N,M(int:整数)
def input2():
	return map(int,input().split())

a,b,k=input2()
MAX=max(a,b)
count=0
ans=0
for i in range(MAX,0,-1):
	if a%i==0 and b%i==0:
		count+=1
		if count==k:
			print(i)
			break