1 #include<cstdio>
 2 #include<iostream>
 3 using namespace std;
 4 int n, ans = 0;
 5 int read() {
 6     char ch = getchar(); int x = 0, f = 1;
 7     while(ch > ‘9‘ || ch < ‘0‘) {if(ch == ‘-‘) f = -1; ch = getchar();}
 8     while(ch >= ‘0‘ && ch <= ‘9‘) {x = x * 10 + ch - ‘0‘ ; ch = getchar();}
 9     return x * f;
10 }
11 int gcd(int a, int b) {
12     if(b == 0) return a;
13     else gcd(b, a % b);
14 }
15 int main() {
16     scanf("%d", &n);
17     for(int i = 1; i <= n; i++) {
18         int x = read();
19         if(x < 0) x = -x;
20         ans = gcd(ans, x);
21     }
22     printf("%d", ans);
23     return 0;
24 }