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 C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<stdio.h>
int main(){
    int A,B,K;
    int st,num;
    int count=0;
    scanf("%d%d%d",&A,&B,&K);
    if(A<B){
        st=B/2;
        num=A;
    }else if(A>B){
        st=A/2;
        num=B;
    }else{
        st=A;
        num=B;
    }
    if(st==0){
        st=1;
    }
    for(int i=st;i>0;i--){
        if(num%i==0){
            count++;
            if(count==K){
                printf("%d\n",i);
            }
        }
    }
}