#include <iostream>
using namespace std;

unsigned long long gcd(unsigned long long m, unsigned long long n)
{
	return (n != 0) ? gcd(n, m%n) : m;
}

int main()
{
	unsigned long long m, n, result;
	cin >> m >> result;
	for (unsigned long long i = 2; i <= m; i++)
	{
		cin >> n;
		result = gcd(result, n);
		if (result == 1) m = 1; //same as break
	}
	cout << result << endl;
	return 0;
}