#include <iostream>

using namespace std;

typedef unsigned long long ullong;

ullong gcd( ullong m, ullong n ) {
	return (n == 0)? m : gcd(n, m%n);
}

int main() {
	int nnum; cin >> nnum;

	ullong num, GCD;

	cin >> num;
	GCD = num;

	for ( int i = 1; i < nnum; i++ )
		cin >> num, GCD = gcd(GCD, 	num);

	cout << GCD << endl;

	return 0;
}