#include <iostream>
#include <fstream>

using namespace std;

int main() {
	int n, a, b, i, r;

	ifstream fin("euclid2.in");
    ofstream fout("euclid2.out");

    fin >> n;
	
	for(i=1; i<=n; i++){
		 fin >> a;
		 fin >> b;
	    }
	while (b!=0){
			r = a %b;
			a = b;
			b = r;
			}
	  fout << a;
	
	return 0;
}