C++ :

#include<cstdio>
#include<cstring>
#include<cmath>
#include<iostream>
#include<algorithm>
using namespace std;

int main()
{
    //freopen("input.txt","r",stdin);
    //freopen("output.txt","w",stdout);
    int a[15];
    int t;
    cin>>t;
    while(t--)
    {
        int n;
        cin>>n;
        for(int i=1;i<=n;i++)
        {
            cin>>a[i];
        }
        int maxn;
        int mina;
        while(1)
        {
             maxn=-9999999;
             mina=9999999;
            int pos1;
            int pos2;
            for(int i=1;i<=n;i++)
            {
                if(a[i]>maxn)
                {
                    pos1=i;
                    maxn=a[i];
                }
                if(a[i]<mina)
                {
                    pos2=i;
                    mina=a[i];
                }
            }
             if(mina==maxn) break;
                a[pos1]=maxn-mina;
                a[pos2]=maxn-mina;
        }
        cout<<maxn<<endl;
    }
    return 0;
}