#include<iostream>
#include<cstdio>
#include<cmath>
#include<string>
#include<queue>
#include<algorithm>
#include<stack>
#include<cstring>
#include<vector>
#include<list>
#include<set>
#include<map>
using namespace std;
const int MAXN=1e5+100,mod=9973,esp=1e-6,inf=0x3f3f3f3f;
typedef long long ll;
const ll INF = (1ll<<60);
int main()
{
    int t,n;
    scanf("%d",&t);
    while(t--)
    {
        scanf("%d",&n);
        int a,ans=0;
        while(n--)
        {
            scanf("%d",&a);
            if(a>ans) ans=a;
        }
        cout<<ans<<endl;
    }
    return 0;
}