#include <iostream>
using namespace std;
int subtraction(int a, int b)
{
	int temp;
	if (a >= b)
	{
		while (b != 0)
		{
			temp = a;
			a = b;
			b = abs(temp - b);          //这里是一个关键，相减的过程中会出现小值减大值的情况，必须让其为正值
		}
		cout << a;
	}
	else
	{
		while (a != 0)
		{
			temp = b;
			b = a;
			a = abs(b - a);
		}
		cout << b;
	}
	return 0;
}
int main()
{
	int i, j;
	cout << "请输入要求公因式的值" << endl;
	cin >> i >> j;
	subtraction(i, j);
	return 0;
}