#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <cmath>
#include <iomanip>
#include <algorithm>
#include<functional>
#include <string>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include<iterator>
#include <stdio.h>
#include <string.h>
#define T int t=0;cin>>t;while(t--)
#define F(i,n) for(ll i=0;i<n;i++)
#define fo(i,a)for(auto&i:a)
#define all(a) a.begin(),a.end()
#define mem(x,y) memset(x,y,sizeof(x))
#define ll long long
#define ld long double
#define endl "\n"
#define vl vector<ll>
#define vi vector<int>
#define cost first
#define from second.first
#define to second.second
#define sz(X) X.size()
using namespace std;
const ll mod = 1000000007;
void code();
///*-*-*-*-*-*-*-*-*-*-*-*-*-*-*>> # str main # <<*-*-*-*-*-*-*-*-*-*-*-*-*-*-*///
int main()
{
    code();
    ll n, m, x, sum = 0, g;
    cin >> n >> m;
    g=__gcd(n,m);
    while(n--)
    {
        cin >> x;
        sum = (sum + (x % g)) % g;
    }
    if(sum)g = 0;
    cout << g;
}
///*-*-*-*-*-*-*-*-*-*-*-*-*-*-*>> # end main # <<*-*-*-*-*-*-*-*-*-*-*-*-*-*-*///
void code()
{
    std::ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    //cout << fixed << setprecision(6);
}