n = int(input())
arr = list(map(int, input(). split()))
ans = min(arr)
for i in arr:
if i % ans:
ans = -1
break
print(ans)
#include<bits/stdc++.h>
using namespace std;
#define ll long long int
int main(){
ll n; cin>>n;
ll a[n],x;
for(ll i=0;i<n;i++){
cin>>a[i];
if(i==0) x=a[i];
else x=__gcd(x,a[i]);
}
for(ll i=0;i<n;i++){
if(x==a[i]){
cout<<x; return 0;
}
}
cout<<"-1";
}
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1612A - Distance | 520A - Pangram |
124A - The number of positions | 1041A - Heist |
901A - Hashing Trees | 1283A - Minutes Before the New Year |
1654D - Potion Brewing Class | 1107B - Digital root |
25A - IQ test | 785A - Anton and Polyhedrons |
1542B - Plus and Multiply | 306A - Candies |
1651C - Fault-tolerant Network | 870A - Search for Pretty Integers |
1174A - Ehab Fails to Be Thanos | 1169A - Circle Metro |
780C - Andryusha and Colored Balloons | 1153A - Serval and Bus |
1487C - Minimum Ties | 1136A - Nastya Is Reading a Book |
1353B - Two Arrays And Swaps | 1490E - Accidental Victory |
1335A - Candies and Two Sisters | 96B - Lucky Numbers (easy) |