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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.ArrayList;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		int a, b, k;
		ArrayList<Integer> list = new ArrayList<>();
		
		Scanner scanner = new Scanner(System.in);
		a = scanner.nextInt();
		b = scanner.nextInt();
		k = scanner.nextInt();
		
		scanner.close();
		
		int max = Math.max(a,  b);
		
		for (int i = 1; i <= max; i++) {
			if (a % i == 0 && b % i == 0) {
				list.add(0, i);
			}
		}
		
		System.out.println(list.get(k-1));
	}

}