#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<algorithm>
using namespace std;
#define N 100000010
int a[N];
int main()
{
    int t;
    cin>>t;
    while(t--)
    {
        int n;
        cin>>n;
        int i;
        for(i=0;i<n;++i)
        cin>>a[i];
        sort(a,a+n);
        cout<<a[n-1]<<endl;
    }
    return 0;
}